Patent Description:
Embodiments of the disclosure may be better understood by referencing the accompanying drawings.

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.

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.

<FIG> is a high-level diagram depicting a treatment system <NUM> configured and implemented within a well system in accordance with some embodiments. Treatment system <NUM> includes 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 system <NUM> includes a coiled tubing apparatus that comprises, in part, coiled tubing <NUM> that is initially coiled onto a cylindrical drum <NUM>. Coiled tubing <NUM> comprises relatively flexible, continuous tubing that is withdrawn from cylindrical drum <NUM>, which may be mounted on a truck or other support structure. Coiled tubing <NUM> may 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 tubing <NUM> is typically inserted into and withdrawn from a wellbore <NUM> using a tubing injector <NUM>.

Coiled tubing <NUM> is a multi-tube tubing string comprising multiple, parallel lengths of tubing that each form a distinct fluid flow conduit. Each tube/conduit within coiled tubing <NUM> may comprise, for example, continuous steel and/or aluminum alloy tubing strings. For example, each of the tubes within coiled tubing <NUM> may range in length from <NUM>,<NUM> to <NUM>,<NUM> feet. Each of the conduits within coiled tubing <NUM> may have an outside diameter of from about <NUM> inch to about <NUM> inches. In some embodiments, each of the conduits within coiled tubing <NUM> is generally a cylindrical or tubular-like structure each having a respective axial flowbore. Coiled tubing <NUM> may 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 tubing <NUM> is configured as an injection string that includes two or more separate fluid flow paths. Coiled tubing <NUM> is 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 to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, coiled tubing <NUM> comprises multiple, separate fluid conduits through which each of a respective one or more fluid components are pumped to a downhole treatment tool <NUM> that is coupled to a distal end of coiled tubing <NUM>. Treatment tool <NUM> includes a mixing applicator <NUM> that is configured to mix and discharge the combination of fluid components at a downhole treatment site.

To position and re-position treatment tool <NUM>, coiled tubing <NUM> is injected and withdrawn by a tubing injector <NUM> through a wellbore <NUM> formed within a borehole surface <NUM>. In some embodiments, wellbore <NUM> may be a fully or partially uncased wellbore. In <FIG>, a casing <NUM> is concentrically disposed within wellbore <NUM> to line borehole surface <NUM>. Treatment tool <NUM> is selectively positioned within wellbore <NUM> such that mixing applicator <NUM> is 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 tubing <NUM> may 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 tool <NUM>may further include a control module <NUM> and one or more downhole sensors <NUM> that may be positioned at one or more positions including proximate mixing applicator <NUM>. The downhole sensor <NUM> within treatment tool <NUM> is configured, using various electronics components, to measure and record downhole parameters such as the position and orientation of treatment tool <NUM>. Downhole sensor <NUM> may 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 tool <NUM>. Control module <NUM> includes electronic components for transmitting and receiving signals from a surface processing system, such as a data processing system <NUM> via a telemetry link <NUM>. Control module <NUM> configures and reconfigures downhole sensor <NUM> based on measurement instructions received from data processing system <NUM>. Control module <NUM> also transmits the sensor measurement information, such as pressure and/or temperature information, to data processing system <NUM>. Telemetry link <NUM> includes 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 system <NUM> may operate at or above a terrain surface <NUM> within or proximate to a well head apparatus, for example. Data processing system <NUM> includes processing and storage components configured to receive and process treatment procedure and downhole measurement information to generate flow control signals. Data processing system <NUM> comprises, in part, a computer processor <NUM> and memory device <NUM> configured to execute program instructions for generating the flow control signals. A communication interface <NUM> is configured to transmit and receive signals to and from treatment tool <NUM> as well as other devices within treatment system <NUM> including flow control devices.

Data processing system <NUM> is 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 system <NUM> may 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 system <NUM> includes an injection control program <NUM> configured to process downhole measurement information collected and generated by downhole sensor <NUM> as well as input from a user interface <NUM>. Injection control program <NUM> is configured, using a combination or program instructions and calls to control activation of flow control devices including a set of pumps <NUM> and <NUM>. Some of all flow control operations may be performed in the absence or otherwise independently of control module <NUM> and/or downhole sensor <NUM>. In such instances, the individual and/or combined flows through coiled tubing <NUM> and treatment tool <NUM> are controlled manually, based on treatment site or other downhole conditions interpreted from surface data.

Each of pumps <NUM> and <NUM> comprises a fluid transfer pump such as a positive-displacement pump. Each of pumps <NUM> and <NUM> is configured to drive fluid from a respective fluid component source through one of the fluid conduits within coiled tubing <NUM> and to a fluid stop point or through a discharge port within treatment tool <NUM>. For example, pump <NUM> is configured to receive fluid from either or both first and second fluid component sources, FC1 and FC2. Pump <NUM> is configured to receive fluid from a third fluid component source, FC3. Pumps <NUM> and <NUM> are configured to drive input fluid from a respective one or more sources into a respective coiled tubing conduit via inlet ports <NUM> and <NUM>, respectively. Ports <NUM> and <NUM> are fluid inlet and coupling devices disposed on or integral to a drum axis plate <NUM> that remains stationary as drum <NUM> rotates to release coiled tubing <NUM>. Ports <NUM> and <NUM> are configured to mechanically couple the outlet lines from pumps <NUM> and <NUM> to inlets to the respective fluid conduits within coiled tubing <NUM>.

Each of pumps <NUM> and <NUM> may 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 system <NUM> via a telemetry link <NUM>. 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 ports <NUM> or <NUM>. 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 pump <NUM> and/or <NUM> to switch from low flow rate (low pressure) operation to higher flow rate (higher pressure) operation. By issuing coordinated activation and switching instructions to pumps <NUM> and <NUM>, data processing system <NUM> controls and coordinates flows and flow rates of fluids from each of fluid sources FC1, FC2, and FC3 through the separate fluid conduits within coiled tubing <NUM>. Additional flow control, including individual control of flow from the fluid sources FC1, FC2, and FC3 to pumps <NUM> and <NUM> is provided by electronically actuated valves <NUM>, <NUM>, and <NUM>. Each of valves <NUM>, <NUM>, and <NUM> includes a control interface (not depicted) such as in the form of a locally installed microcontroller that receives valve position instructions from data processing system <NUM> via telemetry link <NUM>. 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 system <NUM> may 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 system <NUM> via user interface <NUM>. For instance, user interface <NUM> may 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 interface <NUM> is received and processed by a treatment adapter <NUM>. Treatment adapter <NUM> is configured using any combination of program instructions to interpret the request and select a corresponding treatment procedure routine within a treatment procedure database <NUM>. Each of the procedures, PROCEDURE_1 through PROCEDURE_N, within treatment procedure database <NUM> includes data that specifies relative concentrations of the fluid components and reaction periods for mixtures of the components utilized for a particular treatment. Treatment adapter <NUM> further includes instructions for requesting downhole parameters such as from downhole sensors <NUM> and 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_1 through PROCEDURE N.

For example, treatment adapter <NUM> may identify and select PROCEDURE <NUM> in 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 <NUM> may 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 adapter <NUM> may 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 sensors <NUM> and transmitted by control module <NUM> to data processing system <NUM>. Treatment adapter <NUM> generates an adapted procedure that specifies the transport rates and periods for each of the fluid components to be transported to treatment tool <NUM> via a respective one of the fluid conduits within coiled tubing <NUM>. In association with each of the specified transport rates and periods for each fluid component, the adapted procedure may specify a conduit fluid pressure.

Scheduler <NUM> comprises 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 include 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 adapter <NUM>. 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, scheduler <NUM> determines 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 interface <NUM> to the control interfaces of pumps <NUM> and <NUM> and valves <NUM>, <NUM>, and <NUM> to implement coordinated flow of fluids from fluid sources FC <NUM>, FC2, and FC3 through the respective fluid conduits within coiled tubing <NUM>. For example, scheduler <NUM> may be configured to identify a currently utilized flow control configuration in which valve <NUM> controls flow rate from fluid source FC1 to the inlet of pump <NUM>, valve <NUM> controls flow rate from fluid source FC2 to the inlet of pump <NUM>, and valve <NUM> controls flow rate from fluid source FC3 to the inlet of pump <NUM>. Based on operating parameters of the pumps and valves and the adapted transport and mixing procedure, scheduler <NUM> generates 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 scheduler <NUM> are transmitted to the respect flow control components. In response to the instructions, the flow control components, such as pumps <NUM> and <NUM>, drive respective quantities of fluids from fluids sources FC1, FC2, and FC3 into respective fluid conduits within coiled tubing <NUM>. The fluids are transported via the respective conduits to treatment tool <NUM>. As depicted and described in further detail with reference to <FIG> the fluid conduits within coiled tubing <NUM> are mutually configured to provide separate fluid transport until reaching a mixing applicator such as mixing applicator <NUM>. A variety of multi-conduit transport and mixing applicator configuration may be utilized depending on the type of downhole treatment and other factors.

<FIG> illustrate a fluid delivery apparatus <NUM> is accordance with some embodiments such as the embodiments depicted and described with reference to <FIG>. Fluid delivery apparatus <NUM> includes 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 system <NUM>, apparatus <NUM> may form a distal portion of coiled tubing <NUM> and/or all or a portion of mixing applicator <NUM>. Apparatus <NUM> comprises a conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with a conduit <NUM> that may form the outer layer of an injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduit <NUM> and conduit <NUM> form 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 fluid <NUM> received at an inlet of conduit <NUM> and a second fluid <NUM> received at an inlet of second conduit <NUM>. First fluid <NUM> and/or second fluid <NUM> may be loaded within the first and second conduits <NUM> and <NUM>, respectively, prior to initiation of downhole mixing during a treatment operation. First fluid <NUM> and second fluid <NUM> are transported to a mixing applicator formed by or proximate to outlet <NUM> of conduit <NUM> and outlet <NUM> of conduit <NUM>.

In the depicted embodiment, the mixing applicator may be formed, in part, by the relative positioning of outlets <NUM> and <NUM>. As shown in <FIG>, outlet <NUM> is axially offset from outlet <NUM> within the enclosed channel <NUM> of conduit <NUM>. In this manner, the mixing applicator is formed by outlets <NUM> and <NUM> and their relative positioning that forms a confluence region <NUM> in which fluid <NUM> is discharged. Within confluence region <NUM>, discharged fluid <NUM> intersects with the flow path of fluid <NUM> within conduit <NUM> and at the discharge outlet <NUM>.

Apparatus <NUM> may be installed as part of and/or on an injection tool string such as the injection string comprising coiled tubing <NUM> in <FIG>. In such a configuration, the fluid provided by fluid source FC3 may be input to and pressurized by pump <NUM> into conduit <NUM>, which forms an inner conduit within coiled tubing <NUM>. An outer conduit of coiled tubing <NUM> that surrounds conduit <NUM> is formed by conduit <NUM> through which fluids from sources FC1 and/or FC2 are driven by pump <NUM>. In this configuration, and when discharged concurrently, the fluid from source FC3 mixes with fluids from sources FC1 and/or FC2 within confluence region <NUM> proximate a downhole treatment site. The relative timing of fluid transport through conduits <NUM> and <NUM> via valves <NUM>, <NUM>, and <NUM>, and pumps <NUM> and <NUM> may be controlled in accordance with a treatment schedule implemented by a control program such as injection control program <NUM> in <FIG>. 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 conduits <NUM> and <NUM>.

<FIG>, as well as <FIG>, depict the confluence region, such as confluence region <NUM>, as being at least partially contained within conduit <NUM>. Other embodiments may include a mixing applicator in which the conduit outlets, such as outlets <NUM> and <NUM>, are substantially aligned such that the confluence region is formed primarily or completely outside all of the fluid transport conduits.

<FIG> illustrate a fluid delivery apparatus <NUM> is accordance with some embodiments such as the embodiments depicted and described with reference to <FIG>. Fluid delivery apparatus <NUM> includes 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 system <NUM>, apparatus <NUM> may form a distal portion of coiled tubing <NUM> and/or all or a portion of mixing applicator <NUM>.

Apparatus <NUM> comprises a pair of conduits <NUM> and <NUM> that are co-extensively disposed within a conduit <NUM> that may form the outer layer of an injection string. A first enclosed channel <NUM> is formed within conduit <NUM>, a second enclosed channel <NUM> is formed within conduit <NUM>, and a third enclosed channel <NUM> is formed between the outer surfaces of conduits <NUM> and <NUM> and the inner surface of conduit <NUM>.

In this configuration, conduits <NUM>, <NUM>, and <NUM> form 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 fluid <NUM> received at an inlet of conduit <NUM>, a second fluid <NUM> received at an inlet of conduit <NUM>, and a third fluid <NUM> received at an inlet of conduit <NUM> to a downhole mixing applicator.

First fluid <NUM>, second fluid <NUM>, and third fluid <NUM> are transported through conduits <NUM>, <NUM>, and <NUM>, respectively, to a mixing applicator formed by or proximate to outlets <NUM>, <NUM>, and <NUM>.

In the depicted embodiment, the mixing applicator may be formed, in part, by the relative positioning of outlets <NUM>, <NUM>, and <NUM>. As shown in <FIG>, outlets <NUM> and <NUM> are axially offset from outlet <NUM> within the enclosed channel <NUM> of conduit <NUM>. In this manner, the mixing applicator is formed by outlets <NUM>, <NUM>, and <NUM> and their relative positioning that forms a confluence region <NUM> in which first and second fluids <NUM> and <NUM> are discharged sequentially or in partial or full concurrence with the discharge of third fluid <NUM> within confluence region <NUM>. Within confluence region <NUM>, discharged fluids <NUM> and <NUM> mutually intersect and intersect with the flow path of fluid <NUM> within conduit <NUM> and at the discharge outlet <NUM>.

Apparatus <NUM> may be installed as part of and/or on an injection tool string such as the injection string comprising coiled tubing <NUM> in <FIG>. In such a configuration, the fluid within fluid source FC3 may be input to and pressurized by pump <NUM> into conduit <NUM>, which forms an outer conduit of coiled tubing <NUM>. Inner conduits of coiled tubing <NUM> within conduit <NUM> are formed by conduits <NUM> and <NUM> through which fluids from sources FC1 and/or FC2 are input and driven by valves <NUM> and <NUM> and pump <NUM>. In this configuration, and when discharged concurrently, the fluid from source FC3 mixes with fluids from sources FC1 and/or FC2 within confluence region <NUM> proximate a downhole treatment site. As with apparatus <NUM> and any other multi-conduit configuration, the relative timing of fluid transport through conduits <NUM>, <NUM>, and <NUM> via valves <NUM>, <NUM>, and <NUM>, and pumps <NUM> and <NUM> may be controlled in accordance with a treatment schedule implemented by a control program such as injection control program <NUM>. 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 conduits <NUM>, <NUM>, and <NUM>.

<FIG> illustrates a treatment apparatus <NUM> having a mixing applicator comprising dual internal mixing subs in accordance with some embodiments. As with the apparatuses depicted in <FIG>, treatment apparatus <NUM> includes 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 system <NUM> in <FIG>, treatment apparatus <NUM> may form a distal portion of coiled tubing <NUM> and/or all or a portion of mixing applicator <NUM>. Treatment apparatus <NUM> comprises an inner conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit <NUM> that may form the outer layer of a coiled tubing injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduits <NUM> and <NUM> form 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 fluid <NUM> received at an inlet of conduit <NUM> and a second fluid <NUM> received at an inlet of second conduit <NUM>. First fluid <NUM> and second fluid <NUM> are transported to a mixing applicator formed by a two-stage internal mixing sub comprising an inner mixing sub <NUM> and an outer mixing sub <NUM>.

In the depicted embodiment, the mixing applicator may be formed, in part, by the individual and relative configuration of inner and outer mixing subs <NUM> and <NUM>. The mixing applicator includes mixing subs <NUM> and <NUM> that are each configured, in part, as rounded conduit termination caps that form the distal ends of each of conduits <NUM> and <NUM>, respectively. Inner mixing sub <NUM> includes orifices <NUM> that collectively form a distributed and dispersed flow path for fluid <NUM> from channel <NUM> into channel <NUM>. Orifices <NUM> are each substantially smaller in surface area, such as smaller in diameter, than the flow area of channel <NUM>. Configured in this manner, each of orifices <NUM> within the rounded and otherwise substantially enclosed mixing sub <NUM> forms an effective nozzle component through which fluid <NUM> is accelerated that collectively induces radial and/or cyclonic flow into confluence region <NUM>. Mixing sub <NUM> is axially offset from mixing sub <NUM> within the enclosed channel <NUM> of conduit <NUM>. As depicted, the discharge path formed by orifices <NUM> is configured to discharge fluid <NUM> into a first confluence region <NUM> in which fluid <NUM> intersects with the flow of fluid <NUM> within channel <NUM>. The mixing applicator therefore comprises mixing sub <NUM> that is contained within conduit <NUM> and is axially offset from outer mixing sub <NUM> to form first confluence region <NUM> in which fluids <NUM> and <NUM> are initially mixed utilizing the enhanced turbulent nozzle flow provided by orifices <NUM>.

Outer mixing sub <NUM> of the depicted mixing applicator is configured to perform a secondary mixing function as well as a mixture discharge function. Outer mixing sub <NUM> is configured as a fluidic oscillator comprising a rounded end cap that is substantially enclosed at a lower portion in which a second secondary mixture zone <NUM> is formed. Within mixture zone <NUM>, fluids <NUM> and <NUM> continue to mix within the delivery fluid forced applied from channel <NUM> and orifices <NUM>. Outer mixing sub <NUM> includes orifices <NUM> that as depicted are positioned downstream of orifices <NUM> and above a lowermost end of mixing sub <NUM> and collectively provide a discharge outlet for the mixture of fluids <NUM> and <NUM>. Apparatus <NUM> is position downhole, such as by a coiled tubing injection system, such that orifices <NUM> are position at or proximate to a treatment site <NUM> within wellbore <NUM>. Orifices <NUM> may individually and collectively form a smaller flow path than the flow path of channel <NUM> such that the backpressure within mixing sub <NUM> enhances mixture of fluids <NUM> and <NUM> within secondary mixing zone <NUM>.

Apparatus <NUM> may be installed as part of and/or on an injection tool string such as the injection string comprising coiled tubing <NUM> in <FIG>. In such a configuration, the fluid provided by fluid source FC3 may be input to and pressurized by pump <NUM> into conduit <NUM>, which forms an inner conduit within coiled tubing <NUM>. An outer conduit of coiled tubing <NUM> that surrounds conduit <NUM> is formed by conduit <NUM> through which fluids from sources FC1 and/or FC2 are driven by pump <NUM>. In this configuration, and when discharged concurrently, the fluid from source FC3 mixes with fluids from sources FC1 and/or FC2 within confluence region <NUM> and secondary mixing zone <NUM>. The mixed fluid component are discharged through orifices <NUM> at or proximate downhole treatment site <NUM>. The relative timing of fluid transport through conduits <NUM> and <NUM> via valves <NUM>, <NUM>, and <NUM>, and pumps <NUM> and <NUM> may be controlled in accordance with a treatment schedule implemented by a control program such as injection control program <NUM> in <FIG>. 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 conduits <NUM> and <NUM>.

Regarding the various embodiments depicted in <FIG> as well as <FIG>, 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 valves <NUM>, <NUM>, and <NUM>, and pumps <NUM> and <NUM> may 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> depicts a treatment apparatus <NUM> having a mixing applicator configured in part as an external mixing sub in accordance with some embodiments. As with the apparatuses depicted in <FIG>, and <FIG> treatment apparatus <NUM> includes 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 system <NUM> in <FIG>, treatment apparatus <NUM> may form a distal portion of coiled tubing <NUM> and/or all or a portion of mixing applicator <NUM>. Treatment apparatus <NUM> comprises an inner conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit <NUM> that may form the outer layer of a coiled tubing injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduits <NUM> and <NUM> form 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 fluid <NUM> received at an inlet of conduit <NUM> and a second fluid <NUM> received at an inlet of second conduit <NUM>. First fluid <NUM> and second fluid <NUM> are 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 sub <NUM> and a mud motor <NUM> that drives a cutting tool <NUM> for cutting material from structures on or within casing <NUM> and/or otherwise within wellbore <NUM>. In combination, the components of the milling tool are configured to cut/grind material within wellbore <NUM> and remove the resultant debris. In some embodiments, fluid <NUM> flows through inner conduit <NUM> and into mud motor <NUM> to power mud motor <NUM> to drive cutting tool <NUM>. Fluid <NUM> further flows into and through cutting tool <NUM> via discharge orifices <NUM> to form an upward flow pressure within wellbore <NUM>. Flowing downward through cutting tool <NUM> may provide lubrication and cooling for cutting tool <NUM> during operation. Flowing upward into wellbore <NUM> from orifices <NUM>, fluid <NUM> provides a debris transport medium to transport the debris uphole.

In some embodiments, fluid <NUM> may also be utilized to facilitate milling operations such as by serving as a liquid or gaseous solvent that may or may not interact with fluid <NUM> to perform a milling function such as removing and/or dissolving debris, sealing portions of formation wall exposed by the cutting, etc. Apparatus <NUM> is configured to discharge fluid <NUM> at a relative position within the overall milling tool such that exposure of lower milling tool components including mud motor <NUM> to fluid <NUM> is reduced or prevented. External mixing sub <NUM> includes structural features and components configured to direct the flow of the fluid <NUM> within the outer conduit <NUM> to exit the milling tool assembly prior to passing through the lower components including mud motor <NUM> and cutting tool <NUM>. External mixing sub <NUM> includes a lower annular surface <NUM> through which conduit <NUM> passes but that substantially seals channel <NUM> of conduit <NUM>. External mixing sub <NUM> further includes a set of one or more orifices <NUM> disposed above lower surface <NUM> and that provide a flow path from channel <NUM> into wellbore <NUM>. A confluence region in formed <NUM> in which the upward flow of fluid <NUM> intersects the discharge flow of fluid <NUM> from orifices <NUM> to enable mixing for embodiments in which fluids <NUM> and <NUM> are intended to be mixed in furtherance of the milling procedure.

As depicted and described with reference to <FIG>, 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. <FIG> depict 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 to <FIG>.

<FIG> illustrate a mixing applicator <NUM> that includes a flapper type valve configured to control downhole mixture timing and treatment application in accordance with some embodiments. Mixing applicator <NUM> includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator <NUM> comprises an inner conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit <NUM> that may form the outer layer of an injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduits <NUM> and <NUM> form 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 fluid <NUM> through conduit <NUM> and a second fluid <NUM> through outer conduit <NUM>.

Mixing applicator <NUM> further includes a pressure-sensitive flapper valve <NUM> that terminates conduit <NUM>. Flapper valve <NUM> comprises a flow path in which flappers <NUM> are positioned as depicted in <FIG> to stop the flow of fluid <NUM>. Flappers <NUM> include pressure-sensitive hinges that maintain a stop flow position until pressure applied by fluid <NUM> reaches a specified threshold pressure. Once the specified threshold pressure of fluid <NUM> within conduit <NUM> is met or exceeded, flappers <NUM> change position as shown in <FIG> to an open position. Once flappers <NUM> are in the open position, fluid <NUM> flows through flapper valve <NUM> and into a confluence region <NUM> in which is intersects and mixes with fluid <NUM>. Depending on the discharge configuration, such as depicted in <FIG>, the mixture is discharged at or proximate to a treatment site.

<FIG> depict a mixing applicator <NUM> that includes a spring type valve configured to control downhole mixture timing and treatment application in accordance with some embodiments. Mixing applicator <NUM> includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator <NUM> comprises an inner conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit <NUM> that may form the outer layer of an injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduits <NUM> and <NUM> form 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 fluid <NUM> through conduit <NUM> and a second fluid <NUM> through outer conduit <NUM>.

Mixing applicator <NUM> further includes a pressure-sensitive spring valve <NUM> that terminates conduit <NUM>. Spring valve <NUM> comprises a flow path in which spring stopper <NUM> is positioned as depicted in <FIG> to stop the flow of fluid <NUM>. Spring stopper <NUM> is pressure-sensitive to maintain a stop flow position until a pressure applied by fluid <NUM> reaches a specified threshold pressure. Once the specified threshold pressure applied by fluid <NUM> is met or exceeded, spring stopper <NUM> changes position as shown in <FIG> to an open position. With spring stopper <NUM> in the open position, fluid <NUM> flows through spring valve <NUM> and into a confluence region <NUM> in which is intersects and mixes with fluid <NUM>. Depending on the discharge configuration, such as depicted in <FIG>, the mixture is discharged at or proximate to a treatment site.

<FIG> illustrate a mixing applicator <NUM> that includes a rupture disk flow control component configured to control downhole mixture timing and treatment application in accordance with some embodiments. Mixing applicator <NUM> includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator <NUM> comprises an inner conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit <NUM> that may form the outer layer of an injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduits <NUM> and <NUM> form 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 fluid <NUM> through conduit <NUM> and a second fluid <NUM> through outer conduit <NUM>.

Mixing applicator <NUM> further includes a pressure-sensitive rupture disk valve <NUM> that terminates conduit <NUM>. Rupture disk valve <NUM> comprises a flow path in which a frangible disk <NUM> is positioned as depicted in <FIG> to stop the flow of fluid <NUM>. Frangible disk <NUM> is pressure-sensitive to maintain a stop flow position until a pressure applied by fluid <NUM> reaches a specified threshold pressure. Once the specified pressed applied by fluid <NUM> is met or exceeded, frangible disk <NUM> breaches as shown in <FIG> and provides an open flow path. With frangible disk <NUM> in the open position, fluid <NUM> flows through rupture disk valve <NUM> and into a confluence region <NUM> in which fluid <NUM> intersects and mixes with fluid <NUM>. Depending on the discharge configuration, such as depicted in <FIG>, the mixture is discharged at or proximate to a treatment site.

<FIG> depict a mixing applicator <NUM> that includes serially deployed fluid containment plugs configured to sequentially control fluid component mixing in accordance with some embodiments. Mixing applicator <NUM> includes components and features for mixing multiple separately transported fluids at or proximate to a downhole treatment site. Mixing applicator <NUM> comprises an inner conduit <NUM> concentrically disposed within and coextensively aligned in parallel proximity with an outer conduit <NUM> that may form the outer layer of an injection string. A first enclosed channel <NUM> is formed within conduit <NUM> and a second enclosed channel <NUM> is formed between the outer surface of conduit <NUM> and the inner surface of conduit <NUM>. In this configuration, conduits <NUM> and <NUM> form 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 conduit <NUM> and a second fluid <NUM> through outer conduit <NUM>.

Mixing applicator <NUM> further comprises a fluid containment plug assembly including a plug seat <NUM> that terminates conduit <NUM> and a series of one or more dart plugs such as plugs <NUM> and <NUM>. Plug seat <NUM> is 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 plugs <NUM> and <NUM> may be seated during sequential phases of a multi-fluid downhole treatment. <FIG> illustrates a configuration of mixing applicator <NUM> during a first depicted phase of a downhole treatment. During the first phase, fluid <NUM> flows through channel <NUM> to an outlet <NUM> of conduit <NUM> and a fluid <NUM> flows through channel <NUM>, driving dart plug <NUM> toward plug seat <NUM>.

As shown in <FIG>, the volume of fluid <NUM> is contained within conduit <NUM> behind dart plug <NUM> when dart plug <NUM> seats at a second phase. During or following transports of the volume of fluid <NUM> and dart plug <NUM>, a volume of a second fluid <NUM> is input and flows through conduit <NUM> behind a second dart plug <NUM>. Dart plugs <NUM> and <NUM> are configured as frangible plugs that stop flow when seated or otherwise unbreached within conduit <NUM>. Dart plugs <NUM> and <NUM> are configured breach to allow flow through at respectively design breach pressures. For example, a lead plug such as dart plug <NUM> may be designed with a breach pressure that is lower than the breach pressure of following plug such as plug <NUM>. During the second phase depicted in <FIG>, the volume of fluid <NUM> is contained within conduit <NUM> between seated dart plug <NUM> and dart plug <NUM>, and the volume of fluid <NUM> is concurrently contained behind dart plug <NUM>. A series of control signals may be transmitted to pumps (depicted and described with reference to <FIG>) that apply fluid pressure to the fluid column that includes the volumes of fluids <NUM> and <NUM>, or for systems without a control program <NUM> or downhole sensors <NUM> / command module <NUM>, 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 plugs <NUM> and <NUM> have reached the end of tubing.

Once the specified pressed applied to the fluid column reaches a design breach point at a third phase, dart plug <NUM> breaches as shown in <FIG> and provides an open flow path. During the third phase, fluid <NUM> flows through ruptured dart plug <NUM> and into a confluence region <NUM> in which fluid <NUM> intersects and mixes with fluid <NUM>. Depending on the discharge configuration, such as depicted in <FIG>, the mixture is discharged at or proximate to a treatment site. Following discharge of fluid <NUM>, dart plug <NUM> seats in plug seat <NUM> to temporarily contain the volume of fluid <NUM> within conduit <NUM> pending a subsequent mixture phase. Subsequent phases may be performed, for instance, in which pump pressure control is applied to breach dart plug <NUM> to permit fluid <NUM> to intermix with fluid <NUM> within confluence region <NUM>.

<FIG> is a flow diagram illustrating operations and functions for applying a multicomponent fluid treatment in accordance with some embodiments. The operations and functions in <FIG> may be performed by systems, subsystems, devices, and components depicted and described in <FIG> and <NUM>. For example, injection control system <NUM> in <FIG> may be configured to perform one or more of the operations and functions depicted and/or described with reference to <FIG>. The process begins as shown at block <NUM> with an injection scheduler component, such as treatment adapter <NUM>, 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 block <NUM>, 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 block <NUM> may further include determining downhole environment parameters such as fluid pressure(s) within the fluid conduits. At block <NUM>, the data processing system in conjunction with downhole sensors such as downhole sensors <NUM> determine treatment site environment information such as downhole temperature, pressure, and treatment site material composition.

As shown at block <NUM>, a scheduling component of the injection controller, such as scheduler <NUM>, 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 blocks <NUM> and <NUM>. In some embodiments, in which downhole valving control components such as those depicted in <FIG> are 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 pumps <NUM> and <NUM> and valves <NUM>, <NUM>, and <NUM> in <FIG>.

As shown at block <NUM>, the data processing system loads and executes the one or more transport and mixing schedules generated at block <NUM>. 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 block <NUM>, 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 (block <NUM>). As shown at flow control block <NUM>, 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 block <NUM>, a downhole parameter such as downhole temperature and/or fluid conduit pressure exceed a specified threshold value, control returns to block <NUM>. At block <NUM>, 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 blocks <NUM> and <NUM>. The downhole treatment execution with downhole parameter monitoring control continues until the treatment is completed as determined at sequence control block <NUM>.

<NUM> is 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 processor <NUM> (possibly including multiple processors, multiple cores, multiple nodes, and/or implementing multi-threading, etc.). The computer system includes a memory <NUM>. The memory <NUM> may 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 bus <NUM> (e.g., PCI, ISA, PCI-Express, InfiniBand® bus, NuBus, etc.) and a network interface <NUM> which may comprise a Fiber Channel, Ethernet interface, SONET, or other interface.

The system also includes an injection control system <NUM>, which may comprise hardware, software, firmware, or a combination thereof. Injection control system <NUM> may be configured similarly to injection control system <NUM> in <FIG>. For example, injection control system <NUM> may comprise instructions executable by the processor <NUM>. Any one of the previously described functionalities may be partially (or entirely) implemented in hardware and/or on the processor <NUM>. For example, the functionality may be implemented with an application specific integrated circuit, in logic implemented in the processor <NUM>, in a co-processor on a peripheral device or card, etc. Injection control system <NUM> generates 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 in FIG. <NUM> (e.g., video cards, audio cards, additional network interfaces, peripheral devices, etc.).

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.

The flowcharts are provided to aid in understanding the illustrations and are not to be used to limit scope of the claims. The flowcharts depict example operations that can vary within the scope of the claims. Additional operations may be performed; fewer operations may be performed; the operations may be performed in parallel; and the operations may be performed in a different order. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by program code. The program code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable machine or apparatus.

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.

Claim 1:
A downhole treatment apparatus (<NUM>) comprising:
a first conduit (<NUM>) configured to transport a first fluid from a first fluid source through a first enclosed channel (<NUM>) to a first outlet (<NUM>);
a second conduit (<NUM>) configured to transport a second fluid from a second fluid source through a second enclosed channel (<NUM>) to a second outlet (<NUM>);
one or more downhole sensors (<NUM>);
a data processing system (<NUM>) comprising a treatment procedure database (<NUM>), wherein the data processing system is configured to:
select, via the treatment procedure database, a treatment procedure from a plurality of treatment procedures, wherein the selected treatment procedure includes relative fluid concentrations and reaction periods;
request downhole parameters from said one or more down hole sensors; and
generate one or more fluid component transport and mixing timings based, at least in part, on the downhole parameters and reaction periods; and
a mixing applicator (<NUM>) that includes the first outlet (<NUM>) 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 (<NUM>) within or external to the second conduit (<NUM>)