A downhole treatment system, apparatus, and methods are disclosed. In some embodiments a treatment apparatus includes a first conduit configured to transport a first fluid from a first fluid source through a first enclosed channel to a first outlet. A second conduit is configured to transport a second fluid from a second fluid source through a second enclosed channel to a second outlet. The treatment apparatus further comprises a mixing applicator that includes the first outlet positioned to provide a discharge path for the first fluid that at least partially intersects a flow path of the second fluid within a confluence region within or external to the second conduit.

BACKGROUND

During or following drilling, post-drilling, and production phases, several types of downhole treatment operations may be performed. Some such downhole treatment operations may entail transporting and applying fluids or semi-fluid composite materials such as chemical treatments and slurries downhole. For example, a cement slurry comprising multiple distinct and mutually reactive liquids as well as solid components may be delivered via a tubular conduit such as a wellbore casing. To cement the casing within surrounding earth material, the cement is pressure driven downward through the bottom of the casing and up into an annular channel between the outside of the casing and the surrounding earth material. Other downhole treatments entail application of composite fluids such as sealing materials delivered through tubular injection strings. The composite mixtures are typically formed at the surface where mixing devices are utilized to combine the various components prior to the resultant mixture being transported downhole via an injection string. For some applications, multiple components may be delivered sequentially through the injection string, using dart plugs to separate quantities of the respective fluid components.

DESCRIPTION OF EMBODIMENTS

The description that follows includes example systems, methods, techniques, and program flows that embody embodiments of the disclosure. However, it is understood that this disclosure may be practiced without one or more of these specific details. In other instances, well-known instruction instances, protocols, structures and techniques have not been shown in detail in order not to obfuscate the description.

Overview

Wellbore construction and maintenance during drilling, testing, and production may include treatment operations that require delivery of fluids, such as liquids, slurries, and other types of liquid/fluid mixtures to specified downhole sites. Such composite fluids and mixtures sometimes include individual material components that are mutually reactive in a manner that is time-sensitive and/or sensitive to environmental conditions such as temperature and pressure. In such cases, the mixing and placement of such combined composite material is likewise time-sensitive and/or sensitive to environmental conditions such as temperature and pressure.

Embodiments disclosed herein include systems, devices, components, operations, and functions operatively configured to deliver the composite materials by individually transporting the constituent components or combinations of such components. Each of two or more fluid components may be transported over separate flow paths until the components reach a mixing applicator. The transport of the components may be based on a transport and mixing schedule that may be derived, in part, from a treatment procedure. For transport, an injection string includes multiple fluid conduits each transporting a respective fluid component comprising a uniform liquid substance or a mixture of liquid and dissolved or suspended particulate substance(s). For mixing, the injection string includes a mixing applicator that includes outlets of the two or more of the fluid conduits mutually positioned to provide one or more intersecting discharge paths. One or more flow pressure devices, such as fluid pumps, are operably configured to apply flow pressure within the fluid conduits to transport the fluids to a mixing applicator. As utilized herein, a “fluid component” refers to a liquid or gaseous material that includes one or more distinct chemical components such as distinct elements, compounds, etc. Furthermore, a fluid component may comprise a homogeneous or heterogeneous liquid mixture that may be entirely fluid (purely a combination of liquid and dissolved solids) or may contain undissolved solids immersed within fluid.

In some embodiments, a method for placing a multi-component fluid treatment comprises driving a first fluid component through a first conduit to a first outlet and driving a second fluid component through a second conduit to a second outlet. The second conduit is coextensively disposed in substantially parallel proximity with the first conduit. The first and second fluid components are combined within a confluence region that includes at least a portion of a discharge flow path from the first outlet. An injection delivery program is configured to control timing of discharge of the respective fluid components from each of the fluid conduits such as by controlling the respective timing of initial transport and the pressures at which the fluids are pumped downhole.

Example Illustrations

FIG.1is a high-level diagram depicting a treatment system100configured and implemented within a well system in accordance with some embodiments. Treatment system100includes subsystems, devices, and components configured to apply a multi-component treatment using delivery systems and components that transport and mix the multiple fluid components and discharge the mixture at one or more treatment sites. Treatment system100includes a coiled tubing apparatus that comprises, in part, coiled tubing104that is initially coiled onto a cylindrical drum102. Coiled tubing104comprises relatively flexible, continuous tubing that is withdrawn from cylindrical drum102, which may be mounted on a truck or other support structure. Coiled tubing104may be inserted downhole for substantial lengths before requiring a joining operation to connect another strand of coiled tubing, thereby saving considerable time by comparison to jointed pipe. Coiled tubing104is typically inserted into and withdrawn from a wellbore107using a tubing injector106.

Coiled tubing104is a multi-tube tubing string comprising multiple, parallel lengths of tubing that each form a distinct fluid flow conduit. Each tube/conduit within coiled tubing104may comprise, for example, continuous steel and/or aluminum alloy tubing strings. For example, each of the tubes within coiled tubing104may range in length from 1,000 to 15,000 feet. Each of the conduits within coiled tubing104may have an outside diameter of from about 1 inch to about 4.5 inches. In some embodiments, each of the conduits within coiled tubing104is generally a cylindrical or tubular-like structure each having a respective axial flowbore. Coiled tubing104may be formed of single or composite material as would be appreciated by one of skill in the art such as steel, aluminum, copper, and various metallic alloys, as well as a number of non-metallic compounds, such as fiberglass, plastic, polyurethane, or other materials, or a combination of metallic and non-metallic materials.

Coiled tubing104is configured as an injection string that includes two or more separate fluid flow paths. Coiled tubing104is configured, using various input, output, and intermediary connections, to transport each of two or more individual fluid components to one or more downhole positions proximate to treatment sites. As depicted and described in further detail with reference toFIGS.2,3,4,5,6,7,8, and9, coiled tubing104comprises multiple, separate fluid conduits through which each of a respective one or more fluid components are pumped to a downhole treatment tool112that is coupled to a distal end of coiled tubing104. Treatment tool112includes a mixing applicator114that is configured to mix and discharge the combination of fluid components at a downhole treatment site.

To position and re-position treatment tool112, coiled tubing104is injected and withdrawn by a tubing injector106through a wellbore107formed within a borehole surface108. In some embodiments, wellbore107may be a fully or partially uncased wellbore. InFIG.1, a casing110is concentrically disposed within wellbore107to line borehole surface108. Treatment tool112is selectively positioned within wellbore107such that mixing applicator114is positioned to mix and discharge fluid components from the fluid conduits at one or more treatment sites. In some embodiments, flow control in one or more of the fluid conduits is implemented, at least in part, by flow control devices such as pumps and valves. Individual and/or combined flow control for one or more of the fluid conduits within coiled tubing104may be implemented by automated or manual user inputs based, for example, on treatment site environment information obtained from surface and/or subsurface sensors and gauges. In the same or alternate embodiments, some or all of the flow control associated with downhole treatment may be implemented, at least in part, by programmed scheduler components that utilize treatment site or other down hole environment information in combination with treatment-specific information.

Treatment tool112may further include a control module117and one or more downhole sensors116that may be positioned at one or more positions including proximate mixing applicator114. The downhole sensor116within treatment tool112is configured, using various electronics components, to measure and record downhole parameters such as the position and orientation of treatment tool112. Downhole sensor116may be further configured, using various sensor and support electronics components, to measure and record downhole environment conditions such as downhole pressure and temperature proximate treatment tool112. Control module117includes electronic components for transmitting and receiving signals from a surface processing system, such as a data processing system120via a telemetry link118. Control module117configures and reconfigures downhole sensor116based on measurement instructions received from data processing system120. Control module117also transmits the sensor measurement information, such as pressure and/or temperature information, to data processing system120. Telemetry link118includes transmission media and endpoint interface components configured to employ a variety of communication modes. The communication modes may comprise different signal and modulation types carried using one or more different transmission media such as acoustic, electromagnetic, and optical fiber media.

As shown, data processing system120may operate at or above a terrain surface103within or proximate to a well head apparatus, for example. Data processing system120includes processing and storage components configured to receive and process treatment procedure and downhole measurement information to generate flow control signals. Data processing system120comprises, in part, a computer processor122and memory device124configured to execute program instructions for generating the flow control signals. A communication interface127is configured to transmit and receive signals to and from treatment tool112as well as other devices within treatment system100including flow control devices.

Data processing system120is configured to control various fluid flow control components such as pumps and valves to enable coordinated transport, mixing, and discharge of combined fluid treatments at downhole treatment sites. Data processing system120may collect and utilize input information relating to fluid transport distance(s) and downhole environment conditions to determine schedules for transporting the various fluid components. To this end, data processing system120includes an injection control program125configured to process downhole measurement information collected and generated by downhole sensor116as well as input from a user interface144. Injection control program125is configured, using a combination or program instructions and calls to control activation of flow control devices including a set of pumps136and138. Some of all flow control operations may be performed in the absence or otherwise independently of control module117and/or downhole sensor116. In such instances, the individual and/or combined flows through coiled tubing104and treatment tool112are controlled manually, based on treatment site or other downhole conditions interpreted from surface data.

Each of pumps136and138comprises a fluid transfer pump such as a positive-displacement pump. Each of pumps136and138is configured to drive fluid from a respective fluid component source through one of the fluid conduits within coiled tubing104and to a fluid stop point or through a discharge port within treatment tool112. For example, pump136is configured to receive fluid from either or both first and second fluid component sources, FC1and FC2. Pump138is configured to receive fluid from a third fluid component source, FC3. Pumps136and138are configured to drive input fluid from a respective one or more sources into a respective coiled tubing conduit via inlet ports140and142, respectively. Ports140and142are fluid inlet and coupling devices disposed on or integral to a drum axis plate137that remains stationary as drum102rotates to release coiled tubing104. Ports140and142are configured to mechanically couple the outlet lines from pumps136and138to inlets to the respective fluid conduits within coiled tubing104.

Each of pumps136and138may include a control interface (not depicted) such as in the form of a locally installed activation and switching microcontroller that receives activation and switching instructions from data processing system120via a telemetry link148. For instance, the activation instructions may comprise instructions to activate or deactivate the pump and/or to activate or deactivate pressurized operation by which the pump applies pressure to drive the fluid received from one or more of fluid sources, FC1, FC2, and FC3, to one of inlet ports140or142. Switching instructions may comprise instructions to switch to, from, and/or between different fluid pumping modes. For instance, a switching instruction may instruct the target pump136and/or138to switch from low flow rate (low pressure) operation to higher flow rate (higher pressure) operation. By issuing coordinated activation and switching instructions to pumps136and138, data processing system120controls and coordinates flows and flow rates of fluids from each of fluid sources FC1, FC2, and FC3through the separate fluid conduits within coiled tubing104. Additional flow control, including individual control of flow from the fluid sources FC1, FC2, and FC3to pumps136and138is provided by electronically actuated valves130,132, and134. Each of valves130,132, and134includes a control interface (not depicted) such as in the form of a locally installed microcontroller that receives valve position instructions from data processing system120via telemetry link148. For instance, the valve position instructions may comprise instructions to open, close, or otherwise modify the flow control position of the valve. Individually, or in combination with pump operation instructions, data processing system120may control flow and rate of flow from each of fluid sources, FC1, FC2, and FC3.

An example downhole treatment operation or cycle may begin with a request submitted to data processing system120via user interface144. For instance, user interface144may comprise a combination of hardware and software components for entering and translating user input instructions such as a selection of a specified downhole treatment. A variety of downhole treatments may be requested such as a cement casing request, a well casing repair, a formation sealing operation, etc. A downhole treatment request such as a menu selection that is input via user interface144is received and processed by a treatment adapter126. Treatment adapter126is configured using any combination of program instructions to interpret the request and select a corresponding treatment procedure routine within a treatment procedure database146. Each of the procedures, PROCEDURE_1through PROCEDURE_N, within treatment procedure database146includes data that specifies relative concentrations of the fluid components and reaction periods for mixtures of the components utilized for a particular treatment. Treatment adapter126further includes instructions for requesting downhole parameters such as from downhole sensors116and generates relative timings for transporting and mixing the fluid components downhole based on downhole parameters and reaction periods specified by a selected one of PROCEDURE_1through PROCEDURE_N.

For example, treatment adapter126may identify and select PROCEDURE_2in response to a user interface request/selection. Each of the procedures, such as PROCEDURE_2, comprises data that specifies the constituent fluid components utilized for the requested treatment, the relative concentrations, and values or ranges of total individual and/or mixed volumes of the fluid material. The data within PROCEDURE_2may further specify mixing parameters associated with two or more of the fluids or constituent components of two or more of the fluids. For instance, the data may specify one or more reactions periods associated with mixing two or more of the fluids.

The procedure data may further specify environmental factors such as temperatures and pressures that correspond to reaction periods for mixed fluid components. Based on the procedure data, treatment adapter126may request or otherwise acquire downhole parameter data such as fluid pressures within each of the fluid conduits and temperature and pressure proximate the treatment site. The downhole parameters may be measured by downhole sensors116and transmitted by control module117to data processing system120. Treatment adapter126generates an adapted procedure that specifies the transport rates and periods for each of the fluid components to be transported to treatment tool112via a respective one of the fluid conduits within coiled tubing104. In association with each of the specified transport rates and periods for each fluid component, the adapted procedure may specify a conduit fluid pressure.

Scheduler128comprises program code and data configured to generate a flow control schedule including mutually offset control signals for flow control devices such as pumps and valves. The schedule includes pump activation and switching signals and valve position signals that are mutually offset based on device operating capacities in combination with the flow rate information within the adapted procedure received from treatment adapter126. In this manner, the schedule includes flow control signals that are issued at specified timing points to implement relative timing of pump, valve, and other flow control component operation required to implement the adapted treatment procedure. In some embodiments, scheduler128determines the relative timings of flow control device operation based on the overall flow control configuration.

The pump and valve control signals are transmitted via communications interface127to the control interfaces of pumps136and138and valves130,132, and134to implement coordinated flow of fluids from fluid sources FC1, FC2, and FC3through the respective fluid conduits within coiled tubing104. For example, scheduler128may be configured to identify a currently utilized flow control configuration in which valve130controls flow rate from fluid source FC1to the inlet of pump136, valve132controls flow rate from fluid source FC2to the inlet of pump136, and valve134controls flow rate from fluid source FC3to the inlet of pump138. Based on operating parameters of the pumps and valves and the adapted transport and mixing procedure, scheduler128generates and transmits activation and switching signals to the pump and valve components to implement the adapted procedure.

During execution of a downhole treatment, control instructions generated by scheduler128are transmitted to the respect flow control components. In response to the instructions, the flow control components, such as pumps136and138, drive respective quantities of fluids from fluids sources FC1, FC2, and FC3into respective fluid conduits within coiled tubing104. The fluids are transported via the respective conduits to treatment tool112. As depicted and described in further detail with reference toFIGS.2-9the fluid conduits within coiled tubing104are mutually configured to provide separate fluid transport until reaching a mixing applicator such as mixing applicator114. A variety of multi-conduit transport and mixing applicator configuration may be utilized depending on the type of downhole treatment and other factors.

FIGS.2A and2Billustrate a fluid delivery apparatus200is accordance with some embodiments such as the embodiments depicted and described with reference toFIG.1. Fluid delivery apparatus200includes components and features for separately transporting multiple fluids to and mixing the fluids at or proximate to a downhole treatment site. Deployed within a downhole treatment system, such as system100, apparatus200may form a distal portion of coiled tubing104and/or all or a portion of mixing applicator114. Apparatus200comprises a conduit202concentrically disposed within and coextensively aligned in parallel proximity with a conduit204that may form the outer layer of an injection string. A first enclosed channel203is formed within conduit202and a second enclosed channel205is formed between the outer surface of conduit202and the inner surface of conduit204. In this configuration, conduit202and conduit204form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing. The multi-conduit configuration may be utilized to transport a first fluid206received at an inlet of conduit202and a second fluid208received at an inlet of second conduit204. First fluid206and/or second fluid208may be loaded within the first and second conduits202and204, respectively, prior to initiation of downhole mixing during a treatment operation. First fluid206and second fluid208are transported to a mixing applicator formed by or proximate to outlet212of conduit202and outlet214of conduit204.

In the depicted embodiment, the mixing applicator may be formed, in part, by the relative positioning of outlets212and214. As shown inFIG.2B, outlet212is axially offset from outlet214within the enclosed channel205of conduit204. In this manner, the mixing applicator is formed by outlets212and214and their relative positioning that forms a confluence region210in which fluid206is discharged. Within confluence region210, discharged fluid206intersects with the flow path of fluid208within conduit204and at the discharge outlet214.

Apparatus200may be installed as part of and/or on an injection tool string such as the injection string comprising coiled tubing104inFIG.1. In such a configuration, the fluid provided by fluid source FC3may be input to and pressurized by pump138into conduit202, which forms an inner conduit within coiled tubing104. An outer conduit of coiled tubing104that surrounds conduit202is formed by conduit204through which fluids from sources FC1and/or FC2are driven by pump136. In this configuration, and when discharged concurrently, the fluid from source FC3mixes with fluids from sources FC1and/or FC2within confluence region210proximate a downhole treatment site. The relative timing of fluid transport through conduits202and204via valves130,132, and134, and pumps136and138may be controlled in accordance with a treatment schedule implemented by a control program such as injection control program125inFIG.1. In addition to and/or in association with the relative timing of fluid transport, the injection control program may control the absolute and/or relative pumping pressures applied to the fluids during transport within the respective conduits202and204.

FIGS.2A and2B, as well asFIGS.3A and3B, depict the confluence region, such as confluence region210, as being at least partially contained within conduit204. Other embodiments may include a mixing applicator in which the conduit outlets, such as outlets212and214, are substantially aligned such that the confluence region is formed primarily or completely outside all of the fluid transport conduits.

FIGS.3A and3Billustrate a fluid delivery apparatus300is accordance with some embodiments such as the embodiments depicted and described with reference toFIG.1. Fluid delivery apparatus300includes components and features for transporting multiple fluids to and mixing the fluids at or proximate to a downhole treatment site. Deployed within a downhole treatment system, such as system100, apparatus300may form a distal portion of coiled tubing104and/or all or a portion of mixing applicator114. Apparatus300comprises a pair of conduits302and304that are co-extensively disposed within a conduit306that may form the outer layer of an injection string. A first enclosed channel303is formed within conduit302, a second enclosed channel305is formed within conduit304, and a third enclosed channel307is formed between the outer surfaces of conduits302and304and the inner surface of conduit306.

In this configuration, conduits302,304, and306form a multi-conduit fluid transport component that may be formed from coiled tubing or segmented tubing. The multi-conduit configuration may be utilized to transport a first fluid308received at an inlet of conduit302, a second fluid310received at an inlet of conduit304, and a third fluid312received at an inlet of conduit306to a downhole mixing applicator. First fluid308, second fluid310, and third fluid312are transported through conduits302,304, and306, respectively, to a mixing applicator formed by or proximate to outlets314,316, and318.

In the depicted embodiment, the mixing applicator may be formed, in part, by the relative positioning of outlets314,316, and318. As shown inFIG.3B, outlets314and316are axially offset from outlet318within the enclosed channel307of conduit306. In this manner, the mixing applicator is formed by outlets314,316, and318and their relative positioning that forms a confluence region320in which first and second fluids308and310are discharged sequentially or in partial or full concurrence with the discharge of third fluid312within confluence region320. Within confluence region320, discharged fluids308and310mutually intersect and intersect with the flow path of fluid312within conduit306and at the discharge outlet318.

Apparatus300may be installed as part of and/or on an injection tool string such as the injection string comprising coiled tubing104inFIG.1. In such a configuration, the fluid within fluid source FC3may be input to and pressurized by pump138into conduit306, which forms an outer conduit of coiled tubing104. Inner conduits of coiled tubing104within conduit306are formed by conduits302and304through which fluids from sources FC1and/or FC2are input and driven by valves130and132and pump136. In this configuration, and when discharged concurrently, the fluid from source FC3mixes with fluids from sources FC1and/or FC2within confluence region320proximate a downhole treatment site. As with apparatus200and any other multi-conduit configuration, the relative timing of fluid transport through conduits302,304, and306via valves130,132, and134, and pumps136and138may be controlled in accordance with a treatment schedule implemented by a control program such as injection control program125. In addition to and/or in association with the relative timing of fluid transport, the injection control program may control the absolute and/or relative pumping pressures applied to the fluids during transport within the respective conduits302,304, and306.

FIG.4illustrates a treatment apparatus400having a mixing applicator comprising dual internal mixing subs in accordance with some embodiments. As with the apparatuses depicted inFIGS.2and3, treatment apparatus400includes fluid delivery components for transporting and mixing multiple fluid flows as well as mixture discharge components for applying the mixture at or proximate to a treatment site. Deployed within a downhole treatment system, such as system100inFIG.1, treatment apparatus400may form a distal portion of coiled tubing104and/or all or a portion of mixing applicator114. Treatment apparatus400comprises an inner conduit402concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit404that may form the outer layer of a coiled tubing injection string. A first enclosed channel403is formed within conduit402and a second enclosed channel405is formed between the outer surface of conduit402and the inner surface of conduit404. In this configuration, conduits402and404form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing. The multi-conduit configuration may be utilized to transport a first fluid407received at an inlet of conduit402and a second fluid409received at an inlet of second conduit404. First fluid407and second fluid409are transported to a mixing applicator formed by a two-stage internal mixing sub comprising an inner mixing sub408and an outer mixing sub414.

In the depicted embodiment, the mixing applicator may be formed, in part, by the individual and relative configuration of inner and outer mixing subs408and414. The mixing applicator includes mixing subs408and411that are each configured, in part, as rounded conduit termination caps that form the distal ends of each of conduits402and404, respectively. Inner mixing sub408includes orifices410that collectively form a distributed and dispersed flow path for fluid407from channel403into channel405. Orifices410are each substantially smaller in surface area, such as smaller in diameter, than the flow area of channel403. Configured in this manner, each of orifices410within the rounded and otherwise substantially enclosed mixing sub408forms an effective nozzle component through which fluid407is accelerated that collectively induces radial and/or cyclonic flow into confluence region412. Mixing sub408is axially offset from mixing sub414within the enclosed channel405of conduit404. As depicted, the discharge path formed by orifices410is configured to discharge fluid407into a first confluence region412in which fluid407intersects with the flow of fluid409within channel405. The mixing applicator therefore comprises mixing sub408that is contained within conduit404and is axially offset from outer mixing sub414to form first confluence region412in which fluids407and409are initially mixed utilizing the enhanced turbulent nozzle flow provided by orifices410.

Outer mixing sub414of the depicted mixing applicator is configured to perform a secondary mixing function as well as a mixture discharge function. Outer mixing sub414is configured as a fluidic oscillator comprising a rounded end cap that is substantially enclosed at a lower portion in which a second secondary mixture zone416is formed. Within mixture zone416, fluids407and409continue to mix within the delivery fluid forced applied from channel405and orifices410. Outer mixing sub414includes orifices418that as depicted are positioned downstream of orifices410and above a lowermost end of mixing sub414and collectively provide a discharge outlet for the mixture of fluids407and409. Apparatus400is position downhole, such as by a coiled tubing injection system, such that orifices418are position at or proximate to a treatment site425within wellbore420. Orifices418may individually and collectively form a smaller flow path than the flow path of channel405such that the backpressure within mixing sub414enhances mixture of fluids407and409within secondary mixing zone416.

Apparatus400may be installed as part of and/or on an injection tool string such as the injection string comprising coiled tubing104inFIG.1. In such a configuration, the fluid provided by fluid source FC3may be input to and pressurized by pump138into conduit402, which forms an inner conduit within coiled tubing104. An outer conduit of coiled tubing104that surrounds conduit402is formed by conduit404through which fluids from sources FC1and/or FC2are driven by pump136. In this configuration, and when discharged concurrently, the fluid from source FC3mixes with fluids from sources FC1and/or FC2within confluence region416and secondary mixing zone416. The mixed fluid components are discharged through orifices418at or proximate downhole treatment site425. The relative timing of fluid transport through conduits402and404via valves130,132, and134, and pumps136and138may be controlled in accordance with a treatment schedule implemented by a control program such as injection control program125inFIG.1. In addition to and/or in association with the relative timing of fluid transport, the injection control program may control the absolute and/or relative pumping pressures applied to the fluids during transport within the respective conduits402and404.

Regarding the various embodiments depicted inFIGS.1-4as well asFIGS.5-9, it should be noted that some or all of the flow control signal input may be provided in alternative manners based on alternative input. The activation, switching, and other operational control of one or more of the flow control devices such as valves130,132, and134, and pumps136and138may be implemented in a non-programmed and decentralized manner and/or without use of downhole sensor information. For example, flow control signals may be generated by manual activation of pump and valve actuation components based, at least in part, on surface sensor information.

FIG.5depicts a treatment apparatus500having a mixing applicator configured in part as an external mixing sub in accordance with some embodiments. As with the apparatuses depicted inFIGS.2,3, and4treatment apparatus500includes fluid delivery components for transporting and mixing multiple fluid flows as well as mixture discharge components for applying the mixture at or proximate to a treatment site. Deployed within a downhole treatment system, such as system100inFIG.1, treatment apparatus500may form a distal portion of coiled tubing104and/or all or a portion of mixing applicator114. Treatment apparatus500comprises an inner conduit502concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit504that may form the outer layer of a coiled tubing injection string. A first enclosed channel503is formed within conduit502and a second enclosed channel505is formed between the outer surface of conduit502and the inner surface of conduit504. In this configuration, conduits502and504form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing.

The multi-conduit configuration may be utilized to transport a first fluid507received at an inlet of conduit502and a second fluid509received at an inlet of second conduit504. First fluid507and second fluid509are transported to a mixing applicator that is incorporated in a milling tool that includes cutting components and debris removal components. The milling tool includes an external mixing sub510and a mud motor516that drives a cutting tool518for cutting material from structures on or within casing515and/or otherwise within wellbore520. In combination, the components of the milling tool are configured to cut/grind material within wellbore520and remove the resultant debris. In some embodiments, fluid507flows through inner conduit502and into mud motor516to power mud motor516to drive cutting tool518. Fluid507further flows into and through cutting tool518via discharge orifices519to form an upward flow pressure within wellbore520. Flowing downward through cutting tool518may provide lubrication and cooling for cutting tool518during operation. Flowing upward into wellbore520from orifices519, fluid507provides a debris transport medium to transport the debris uphole.

In some embodiments, fluid509may also be utilized to facilitate milling operations such as by serving as a liquid or gaseous solvent that may or may not interact with fluid507to perform a milling function such as removing and/or dissolving debris, sealing portions of formation wall exposed by the cutting, etc. Apparatus500is configured to discharge fluid509at a relative position within the overall milling tool such that exposure of lower milling tool components including mud motor516to fluid509is reduced or prevented. External mixing sub510includes structural features and components configured to direct the flow of the fluid509within the outer conduit504to exit the milling tool assembly prior to passing through the lower components including mud motor516and cutting tool518. External mixing sub510includes a lower annular surface514through which conduit502passes but that substantially seals channel505of conduit504. External mixing sub510further includes a set of one or more orifices512disposed above lower surface514and that provide a flow path from channel505into wellbore520. A confluence region in formed517in which the upward flow of fluid507intersects the discharge flow of fluid509from orifices512to enable mixing for embodiments in which fluids507and509are intended to be mixed in furtherance of the milling procedure.

As depicted and described with reference toFIGS.1-5, the treatment systems and apparatus may include various fluid transport, mixing, and discharge outlet configurations. The treatment systems and apparatuses may further include various downhole fluid flow isolation components that provide a controlled valve function that may be utilized in combination with the pump and surface valve control of fluid flows and flow rates to implement a multi-fluid downhole treatment.FIGS.6-9depict mixing applicators that integrate valving components such as may be incorporated into one or more of the mixing applicator assemblies depicted and described with reference toFIGS.1-5.

FIGS.6A-6Billustrate a mixing applicator600that includes a flapper type valve configured to control downhole mixture timing and treatment application in accordance with some embodiments. Mixing applicator600includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator600comprises an inner conduit602concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit604that may form the outer layer of an injection string. A first enclosed channel603is formed within conduit602and a second enclosed channel605is formed between the outer surface of conduit602and the inner surface of conduit604. In this configuration, conduits602and604form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing. The multi-conduit configuration may be utilized to transport a first fluid607through conduit602and a second fluid609through outer conduit604.

Mixing applicator600further includes a pressure-sensitive flapper valve608that terminates conduit602. Flapper valve608comprises a flow path in which flappers610are positioned as depicted inFIG.6Ato stop the flow of fluid607. Flappers610include pressure-sensitive hinges that maintain a stop flow position until pressure applied by fluid607reaches a specified threshold pressure. Once the specified threshold pressure of fluid607within conduit602is met or exceeded, flappers610change position as shown inFIG.6Bto an open position. Once flappers610are in the open position, fluid607flows through flapper valve608and into a confluence region612in which is intersects and mixes with fluid609. Depending on the discharge configuration, such as depicted inFIGS.2-5, the mixture is discharged at or proximate to a treatment site.

FIGS.7A-7Bdepict a mixing applicator700that includes a spring type valve configured to control downhole mixture timing and treatment application in accordance with some embodiments. Mixing applicator700includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator700comprises an inner conduit702concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit704that may form the outer layer of an injection string. A first enclosed channel703is formed within conduit702and a second enclosed channel705is formed between the outer surface of conduit702and the inner surface of conduit704. In this configuration, conduits702and704form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing. The multi-conduit configuration may be utilized to transport a first fluid707through conduit702and a second fluid709through outer conduit704.

Mixing applicator700further includes a pressure-sensitive spring valve708that terminates conduit702. Spring valve708comprises a flow path in which spring stopper712is positioned as depicted inFIG.7Ato stop the flow of fluid707. Spring stopper712is pressure-sensitive to maintain a stop flow position until a pressure applied by fluid707reaches a specified threshold pressure. Once the specified threshold pressure applied by fluid707is met or exceeded, spring stopper712changes position as shown inFIG.7Bto an open position. With spring stopper712in the open position, fluid707flows through spring valve708and into a confluence region714in which is intersects and mixes with fluid709. Depending on the discharge configuration, such as depicted inFIGS.2-5, the mixture is discharged at or proximate to a treatment site.

FIGS.8A-8Billustrate a mixing applicator800that includes a rupture disk flow control component configured to control downhole mixture timing and treatment application in accordance with some embodiments. Mixing applicator800includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator800comprises an inner conduit802concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit804that may form the outer layer of an injection string. A first enclosed channel803is formed within conduit802and a second enclosed channel805is formed between the outer surface of conduit802and the inner surface of conduit804. In this configuration, conduits802and804form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing. The multi-conduit configuration may be utilized to transport a first fluid807through conduit802and a second fluid809through outer conduit804.

Mixing applicator800further includes a pressure-sensitive rupture disk valve808that terminates conduit802. Rupture disk valve808comprises a flow path in which a frangible disk812is positioned as depicted inFIG.8Ato stop the flow of fluid807. Frangible disk812is pressure-sensitive to maintain a stop flow position until a pressure applied by fluid807reaches a specified threshold pressure. Once the specified pressed applied by fluid807is met or exceeded, frangible disk812breaches as shown inFIG.8Band provides an open flow path. With frangible disk812in the open position, fluid807flows through rupture disk valve808and into a confluence region814in which fluid807intersects and mixes with fluid809. Depending on the discharge configuration, such as depicted inFIGS.2-5, the mixture is discharged at or proximate to a treatment site.

FIGS.9A-9Cdepict a mixing applicator900that includes serially deployed fluid containment plugs configured to sequentially control fluid component mixing in accordance with some embodiments. Mixing applicator900includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator900comprises an inner conduit902concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit904that may form the outer layer of an injection string. A first enclosed channel903is formed within conduit902and a second enclosed channel905is formed between the outer surface of conduit902and the inner surface of conduit904. In this configuration, conduits902and904form a multi-conduit fluid transport component that may be formed from coiled tubing or straight segmented tubing. The multi-conduit configuration may be utilized to transport a series of one or more fluids through conduit902and a second fluid909through outer conduit904.

Mixing applicator900further comprises a fluid containment plug assembly including a plug seat916that terminates conduit902and a series of one or more dart plugs such as plugs914and918. Plug seat916is formed as an internally annular flange or otherwise to forms an annular seating surface into which a series of one or more dart plugs such as the depicted dart plugs914and918may be seated during sequential phases of a multi-fluid downhole treatment.FIG.9Aillustrates a configuration of mixing applicator900during a first depicted phase of a downhole treatment. During the first phase, fluid909flows through channel905to an outlet912of conduit904and a fluid907flows through channel903, driving dart plug914toward plug seat916.

As shown inFIG.9B, the volume of fluid907is contained within conduit902behind dart plug914when dart plug914seats at a second phase. During or following transports of the volume of fluid907and dart plug914, a volume of a second fluid920is input and flows through conduit902behind a second dart plug918. Dart plugs914and918are configured as frangible plugs that stop flow when seated or otherwise unbreached within conduit902. Dart plugs914and918are configured breach to allow flow through at respectively design breach pressures. For example, a lead plug such as dart plug914may be designed with a breach pressure that is lower than the breach pressure of following plug such as plug918. During the second phase depicted inFIG.9B, the volume of fluid907is contained within conduit902between seated dart plug914and dart plug918, and the volume of fluid920is concurrently contained behind dart plug918. A series of control signals may be transmitted to pumps (depicted and described with reference toFIG.1) that apply fluid pressure to the fluid column that includes the volumes of fluids907and909, or for systems without a control program125or downhole sensors116/command module117, the fluid pressure may be applied manually at any time after a specified fluid volume has been pumped or surface pressure indication is observed, to ensure dart plugs914and918have reached the end of tubing.

Once the specified pressed applied to the fluid column reaches a design breach point at a third phase, dart plug914breaches as shown inFIG.9Cand provides an open flow path. During the third phase, fluid907flows through ruptured dart plug914and into a confluence region922in which fluid907intersects and mixes with fluid809. Depending on the discharge configuration, such as depicted inFIGS.2-5, the mixture is discharged at or proximate to a treatment site. Following discharge of fluid907, dart plug918seats in plug seat916to temporarily contain the volume of fluid920within conduit902pending a subsequent mixture phase. Subsequent phases may be performed, for instance, in which pump pressure control is applied to breach dart plug918to permit fluid920to intermix with fluid909within confluence region922.

FIG.10is a flow diagram illustrating operations and functions for applying a multicomponent fluid treatment in accordance with some embodiments. The operations and functions inFIG.10may be performed by systems, subsystems, devices, and components depicted and described inFIGS.1-9and11. For example, injection control system125inFIG.1may be configured to perform one or more of the operations and functions depicted and/or described with reference toFIG.10. The process begins as shown at block1002with an injection scheduler component, such as treatment adapter126, selecting a multi-component treatment procedure. In some embodiments, the selection encompasses accessing a treatment procedure database in response to a request submitted via a user interface. Each of the selectable treatment procedures comprises information specifying the fluid components, mixtures including relative concentrations of respective components in the mixtures, and component and mixture volumes required for a respective downhole treatment.

As shown at block1004, a data processing system in combination with injection string control components and downhole sensors determine treatment operation parameters such as transport distances for each of the respective separately transported fluids. The determination at block1004may further include determining downhole environment parameters such as fluid pressure(s) within the fluid conduits. At block1006, the data processing system in conjunction with downhole sensors such as downhole sensors116determine treatment site environment information such as downhole temperature, pressure, and treatment site material composition.

As shown at block1008, a scheduling component of the injection controller, such as scheduler128, generates one or more fluid component transport and mixing schedules based the selected treatment procedure and on the fluid conduit pressures and lengths (transport distances) and on treatment site environment parameters determined at blocks1004and1006. In some embodiments, in which downhole valving control components such as those depicted inFIGS.6-9are utilized, the transport and mixing schedules are generated further based on the individual and collective flow control configurations of each of the individual fluid conduits. Each of the one or more generated transport and mixing schedules comprises instructions and data for actuating and otherwise operating flow control devices that control the timing and values of flows, flow rates, and pressures within each of the fluid conduits. The flow control devices may include one or more fluid pumps and valves such as pumps136and138and valves130,132, and134inFIG.1.

As shown at block1010, the data processing system loads and executes the one or more transport and mixing schedules generated at block1008. For instance, the data processing system may execute transport and mixing schedule instructions that transmit a series of flow control signals to the flow control devices. At block1012, implementation of the downhole treatment is effectuated in accordance with the actuation and other operational control of the flow control devices in accordance with the transport and mixing schedule. Namely, the control signals transmitted to the flow control devices and relative timing thereof actuate and otherwise operate the devices in the manner and in the sequentially offset timing implemented by the transport and mixing schedule. During implementation of the downhole treatment including execution of the transport and mixing schedule(s), the data processing system in conjunction with downhole sensors monitors downhole operational and/or environment parameters (block1014). As shown at flow control block1016, the injection control component is further configured to adjust the generated transport and mixing schedule(s) in response to determining that one or more downhole parameters has exceeded a threshold. If, as determined at block1016, a downhole parameter such as downhole temperature and/or fluid conduit pressure exceed a specified threshold value, control returns to block1008. At block1008, the previously generated fluid transport and mixing schedule is adjusted based on the downhole parameter value that exceeds the threshold and the execution sequence recommences at blocks1010and1012. The downhole treatment execution with downhole parameter monitoring control continues until the treatment is completed as determined at sequence control block1018.

Example Computer

FIG.11is a block diagram depicting an example computer system that may be utilized to implement control operations for implementing a multi-component downhole treatment operation in accordance with some embodiments. The computer system includes a processor1101(possibly including multiple processors, multiple cores, multiple nodes, and/or implementing multi-threading, etc.). The computer system includes a memory1107. The memory1107may be system memory (e.g., one or more of cache, SRAM, DRAM, etc.) or any one or more of the above already described possible realizations of machine-readable media. The computer system also includes a bus1103(e.g., PCI, ISA, PCI-Express, InfiniBand® bus, NuBus, etc.) and a network interface1105which may comprise a Fiber Channel, Ethernet interface, SONET, or other interface.

The system also includes an injection control system1111, which may comprise hardware, software, firmware, or a combination thereof. Injection control system1111may be configured similarly to injection control system125inFIG.1. For example, injection control system1111may comprise instructions executable by the processor1101. Any one of the previously described functionalities may be partially (or entirely) implemented in hardware and/or on the processor1101. For example, the functionality may be implemented with an application specific integrated circuit, in logic implemented in the processor1101, in a co-processor on a peripheral device or card, etc. Injection control system1111generates multi-component fluid flow control signals that may be transmitted to flow control devices such as pumps and valves in the manner described above. Additional realizations may include fewer or more components not expressly illustrated inFIG.11(e.g., video cards, audio cards, additional network interfaces, peripheral devices, etc.).

Variations

While the aspects of the disclosure are described with reference to various implementations and exploitations, it will be understood that these aspects are illustrative and that the scope of the claims is not limited to them. In general, techniques for applying multi-component downhole treatments as described herein may be implemented with facilities consistent with any hardware system or systems. Plural instances may be provided for components, operations or structures described herein as a single instance. Finally, boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of the disclosure. In general, structures and functionality presented as separate components in the example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components.

As will be appreciated, aspects of the disclosure may be embodied as a system, method or program code/instructions stored in one or more machine-readable media. Accordingly, aspects may take the form of hardware, software (including firmware, resident software, micro-code, etc.), or a combination of software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable storage medium may be, for example, but not limited to, a system, apparatus, or device, that employs any one of or combination of electronic, magnetic, optical, electromagnetic, infrared, or semiconductor technology to store program code.

Computer program code for carrying out operations for aspects of the disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as the Java® programming language, C++ or the like; a dynamic programming language such as Python; a scripting language such as Perl programming language or PowerShell script language; and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on a stand-alone machine, may execute in a distributed manner across multiple machines, and may execute on one machine while providing results and or accepting input on another machine. The program code/instructions may also be stored in a machine readable medium that can direct a machine to function in a particular manner, such that the instructions stored in the machine readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

Use of the phrase “at least one of” preceding a list with the conjunction “and” should not be treated as an exclusive list and should not be construed as a list of categories with one item from each category, unless specifically stated otherwise.

EMBODIMENTS

An apparatus comprising: a first conduit configured to transport a first fluid from a first fluid source through a first enclosed channel to a first outlet; a second conduit configured to transport a second fluid from a second fluid source through a second enclosed channel to a second outlet; and a mixing applicator that includes the first outlet positioned to provide a discharge path for the first fluid that at least partially intersects a flow path of the second fluid within a confluence region within or external to the second conduit. For Embodiment 1, the apparatus may include a coiled tubing tool string within which the second conduit is coextensively disposed in substantially parallel proximity with respect to the first conduit. For Embodiment 1, the first conduit may be coextensively disposed within the second conduit.

The apparatus of Embodiment 1, wherein the mixing applicator comprises an internal mixing sub in which the first outlet comprises one or more orifices in the first conduit and the second outlet comprises one or more orifices in the second conduit downstream of the one or more orifices in the first conduit. For Embodiment 2, each of the one or more orifices in the first conduit may have a smaller surface area than a flow area through the first conduit. For Embodiments 1-2, the mixing applicator may include a pressure-sensitive flow control component that blocks flow to the first outlet when fluid pressure within the first conduit is below a threshold pressure. For Embodiments 1-2, the mixing applicator may be included in a treatment tool on a tool string and is configured to discharge combined fluid components from the confluence region to a region external to the treatment tool.

The apparatus of Embodiments 1-2, further comprising: at least one flow control device that is configured to control flow of the first fluid through the first conduit and to control flow of the second fluid through the second conduit; and a flow control system configured to operate said at least one flow control device based, at least in part, on a downhole parameter and a treatment procedure. For Embodiment 3, the at least one flow control device may comprise: a first pump having an input port that receives the first fluid and an output port coupled to an inlet of the first conduit; and a second pump having an input port that receives the second fluid and an output port coupled to an inlet of the second conduit.

A method comprising: transporting a first fluid through a first conduit to a first outlet; transporting a second fluid through a second conduit to a second outlet; and combining the first and second fluids within a confluence region that includes at least a portion of a discharge flow path from the first outlet. For Embodiment 4, wherein the first conduit and the second conduit may be included in an injection string having a mixing applicator that includes the first outlet and the second outlet. For Embodiment 4, the first and second fluids may be loaded within the first and second conduits prior to initiation of downhole mixing during a treatment operation. For Embodiment 4, said transporting the first and second fluids may comprise: transporting a volume of the first fluid based on a treatment procedure; and transporting a volume of the second fluid based on the treatment procedure. For Embodiment 4, said transporting the volume of the first fluid may comprise pumping the first fluid at a first rate, and wherein said transporting the volume of the second fluid comprises pumping the second fluid at a second rate determined based, at least in part, on the first rate. For Embodiment 4, said combining the first and second fluids may include discharging the first fluid from the first outlet that is disposed in the confluence region within or external to the second conduit. For Embodiment 4, said transporting a volume of the first fluid and transporting a volume of the second fluid may comprise: in response to a treatment request, selecting the treatment procedure that indicates mixing parameters of the first fluid and the second fluid; determining at least one downhole parameter; and generating a transport and mixing schedule based, at least in part, on the treatment procedure and the at least one downhole parameter. For Embodiment 4, the mixing parameters may include a reaction period associated with at least one environmental parameter. For Embodiment 4, the downhole parameter may be at least one of a fluid pressure of the first conduit, a fluid pressure of the second conduit, and a downhole temperature. For Embodiment 4, said transporting the volume of the second fluid based on the treatment procedure may comprise initiating or terminating transport of the second fluid relative to initiating or terminating transport of the first fluid based, at least in part, on the transport and mixing schedule. For Embodiment 4, the method further comprises mixing the first and second fluids at a point during a treatment operation based on the transport and mixing schedule.