Patent ID: 12203366

DETAILED DESCRIPTION

This specification describes systems and methods for collecting samples from a wellbore while running a gauge cutter through the wellbore. In some wells (e.g., gas wells), liquid condensation can build up on the interior walls of the wellbore or production tubing. As the gas flow decreases, for example due to reduced reservoir pressure from production of gas from the well, the gas no longer has enough energy to lift heavier liquids (e.g., water and longer chain molecules such as heptanes (C7) and larger molecules) to the surface. The mist-like drops of heavier fluids can coalesce together and form droplets on the inner wall of the wellbore or tubing and/or accumulate at the bottom of the well. Often the condensate is disturbed before appropriate logging tools for sampling or analysis are run in the wellbore. The systems and methods of this disclosure provide a way to collect samples of the condensate during the first run of a tool in the wellbore. The systems and methods of this disclosure also provide a way of sampling solid debris from the wellbore as the tool is pulled out of the wellbore.

Maturing reservoir wells over time can experience a reduction in tubing/casing internal diameter due to scale production and accumulation. A gauge cutter can be run through the wellbore to allow accessibility of tubing, casing, and liner for other tools to be run in the wellbore. Gauge cutters can come in different sizes. The size of gauge cutter chosen for a particular application can be dependent on, for example, the inner diameter of the wellbore, the diameter of subsequent tools to be used, or other factors. A gauge cutter can be used to tag the plug back total depth (PBTD), which is the depth of the well to the cement plug placed at the bottom of the producing zone (e.g., the accessible depth in the wellbore). A gauge cutter can also be used to clean a wellbore from soft paraffin and soft scale that has developed over time.

FIGS.1A-1Cshow side, front, and section views of a gauge cutter100configured to collect samples from a wellbore. The gauge cutter100includes a cylindrical body102with an uphole end104and a downhole end106. The uphole end104can include a standard wireline connection108and a fishing neck110to connect to a slickline. The downhole end106includes a cutter blade112. The cutter blade112is configured to scrape cut, scour or dislodge debris from the interior walls of the wellbore. The cylindrical body102can be a single piece. A central recess114is defined within the cylindrical body102extending from the downhole end106toward the uphole end104. The central recess114defines an interior wall116of the cylindrical body102. One or more large openings118are defined in the cylindrical body102allowing access to the central recess114in the uphole portion of the central recess114.

A wiper blade120is disposed around the exterior of the cylindrical body downhole from the large openings118. The wiper blade120can include an elastomeric material or a plastic material. For example, the wiper blade can include polyurethane, silicone, fluoroelastomers, nitrile, polychloroprene, and ethylene propylene diene monomer (EPDM). The wiper blade120is configured to contact the interior walls of the wellbore and wipe condensate from the wellbore. The wiper blade can have an outer diameter larger than an outer diameter of the cylindrical body. The wiper blade can be flexible and configured to bend to allow the gauge cutter to pass through the wellbore. Condensate wiped from the wellbore can coalesce and pool on the downhole side of the wiper blade120.

In some implementations, wiper blade120can include overlapping fingers or flaps. In these implementations, the wiper blade120can include a thin, flexible plastic, for example, polypropylene.

The cylindrical body102includes a plurality of passageways126extending from the exterior of the body102into the central recess114. The plurality of passageways126is downhole from the wiper blade120and positioned to collect condensate wiped from the wellbore. The plurality of passageways126can be evenly spaced around the circumference of the cylindrical body102. Each passageway126can have a small diameter (e.g., 0.05 mm, 1 mm, 2 mm). In some implementations, the plurality of passageways126can include passageways with different diameters. For example, a portion of the plurality of passageways126can have a diameter of 0.05 mm and a second portion of the plurality of passageways126can have a diameter of 2 mm. The plurality of passageways126can be capillary tubes configured to draw liquid from the exterior of the gauge cutter100to the central recess114using capillary forces between the liquid and the interior of the plurality of passageways126. In some implementations, the liquid flows through the plurality of passageways126based on a pressure differential between a pressure exerted on condensate accumulated on the downhole side of the wiper blade120and the pressure inside the condensate collection chamber128.

An annular condensate collection chamber128is disposed within the central recess114adjacent the interior wall116of the cylindrical body102. The condensate collection chamber128is configured to collect condensate from the plurality of passageways126. The condensate collection chamber128can be removable from the cylindrical body102.

In some implementations, the condensate collection chamber128can be defined by a removable core130disposed within the central recess114of the gauge cutter100. The removable core130can be made from plastic, metal, polymer, elastomer or combinations thereof. The removable core130can be attached to the cylindrical body102by a mechanical fastener132, for example, a snap fit connection, magnetic connection, bolted connection, or tongue and groove connection. The removable core130includes an upper seal134and a lower seal136. When inserted into the central recess114, the removable core130defines an annular space138between the wall of the removable core130and the interior walls116of the cylindrical body102. The annular space138is bounded in the uphole direction by the upper seal134and in the downhole direction by the lower seal136. The annular space138can define the condensate collection chamber128.

Uphole of the upper seal134, a second annular space140is defined between the removable core130and the interior walls116of the cylindrical body102. The uphole portion142of the removable core130includes slots144that are fluid permeable. In some implementations, the uphole portion142can include holes and/or a mesh instead of or in addition to slots144. The second annular space140defines a solid debris collection chamber146. When the gauge cutter100is pulled out of the wellbore, the solid collection chamber146can collect solid debris suspended in the fluid within the wellbore.

FIGS.2A-2Cshow front, cross-section, and detail views of an example removable core130. The removable core130includes a tubular core body150with an open central passageway152extending the entire length of the tubular core body150. A downhole portion154of the tubular core body150can have a wall thickness156larger than a wall thickness158of the uphole portion142. The upper seal134can rest on the shoulder160created by the difference in the wall thicknesses156and158. The distance162between the lower seal136and the shoulder160defines the distance between the lower seal136and the upper seal134. The distance162also defines the height of the condensate collection chamber128. The surfaces of the downhole portion154of the tubular core body150are solid (e.g., no holes penetrate the walls of the downhole portion154) and not permeable to fluids. The lower seal136can be integrated with the tubular core body150. In some implementations, the lower seal136can be a separate piece fitted to the tubular core body150. The upper seal134can be a separate piece from the tubular core body150. The upper seal134and lower seal136can include a groove164where a gasket135,137(e.g., an O-ring) can be positioned to form a fluid tight seal with the interior walls116of the gauge cutter100.

FIG.3Aillustrates an example liquid catching sponge180that can be included in some implementations. The liquid catching sponge180can be included in the condensate collection chamber128. The sponge180can assist the retention and collection of condensate samples in the condensate collection chamber128. In some implementations, a liquid catching sponge180can be made wettable to certain fluids. For example, the liquid catching sponge180can be oil wettable, or the sponge180can be water wettable. The type of sponge fitted into the condensate collection chamber128can be bespoke to a condensate expected to be or known to be within the wellbore. In some implementations, the liquid catching sponge180can include multiple types of wettable sponges. In these implementations, the liquid catching sponge180can be configured within the condensate collection chamber128such that the volume of different fluids collected can be estimated from the retrieved condensate samples. In some implementations, the bottom most part182of the liquid catching sponge180can collect liquid accumulated at the bottom of the well.

FIG.3Billustrates an example sensor module190that can be included in some implementations. The sensor module190can include, for example, a fluid detection sensor, a water-cut sensor, a depth sensor, a pressure sensor, or a combination of sensors. The sensor module190can provide additional information on when and where condensate samples are collected during a running-in-hole (RIH) operation. The sensor module190can be housed in an annular housing192and can be disposed within the second annular space140uphole of the upper seal134surrounding the uphole portion142of the removable core130.

The sensor module190can include a battery to provide power to the sensors of the sensor module. The sensor module190can also include a memory to store data and measurements detected by the sensors. The memory can be accessed, and data retrieved from the memory after the gauge cutter100is removed from the wellbore.

In some implementations, the sensor module190can be configured to start collection of condensate samples in the condensate collection chamber128at a pre-defined pressure or depth within the wellbore. In some implementations, a fluid detection sensor can be configured to detect concentrations of a particular fluid or multiple fluids (e.g., hydrogen sulfide, carbon dioxide, heptane).

FIG.4Aillustrates a cross-section view of an example gauge cutter200including a sensor module190and a liquid catching sponge180. The liquid catching sponge180is included within the condensate collection chamber128. The sensor module190is included within the second annular space140uphole of the upper seal134. The solid debris collection chamber146is uphole of the sensor module190.

FIGS.4B-4Cshow example configurations of gauge cutters210,212. Gauge cutters can be configured to match desired volumes for condensate collection and solid debris collection according to the specific application or wellbore without changing the overall design of the gauge cutter.FIG.4Bshows gauge cutter210which includes a longer condensate collection chamber214and a smaller solid debris collection chamber216as compared with gauge cutters100or200.FIG.4Cillustrates a gauge cutter212that includes a larger solid debris collection chamber220and a smaller condensate collection chamber222. In some implementations, the total length224of the gauge cutter210or212can remain the same while the lengths of the sample collection chambers are altered. In some implementations, the total length224of the gauge cutter and the lengths of the condensate and solid debris sample collection chambers can be customized without changing the tool functionality.

FIG.5is a flow chart of an example method250for collecting samples from a wellbore. The method250includes using a gauge cutter including a wiper blade disposed around the exterior circumference of the gauge cutter and a sample collection chamber interior to the gauge cutter (e.g., gauge cutter100). The gauge cutter is moved in a downhole direction (252). The gauge cutter can be the first tool run in a wellbore to cut a clear path through debris (e.g., paraffin or scaling) that would otherwise prevent subsequent tools from being run through the wellbore. The sample collection chamber of the gauge cutter can include a condensate collection chamber and a solids collection chamber.

Condensate on interior walls of the wellbore is wiped by the wiper blade of the gauge cutter (254). Condensate (e.g., water and hydrocarbons) can form on the interior walls of the borehole. The condensate can be collected in a condensate collection chamber of the gauge cutter (256). In some implementations, the condensate collection can begin at a specified depth or pressure within the wellbore. In some implementations, a sensor module records locations and other properties (e.g., pressure) within the wellbore where condensate is collected. In some implementations, a sample of liquid from the bottom of the wellbore is collected in the condensate collection chamber. In some cases, the samples of condensate are retained by a liquid catching sponge disposed within the condensate collection chamber.

FIG.6shows a cross section of a wellbore300and a gauge cutter302illustrating wiping of condensate304from the wellbore300while the gauge cutter302is moved in a downhole direction306(e.g., RIH). A wiper blade308of the gauge cutter302contacts the interior walls310of the wellbore300. As the gauge cutter302moves downhole, condensate304that has formed on the interior walls310of the wellbore300accumulates in a pool312on the downhole side of the wiper blade308. The pool312of condensate304can grow large enough to contact openings of passageways314that extend from the exterior316of the gauge cutter302into a condensate collection chamber318disposed adjacent the interior surface320of the gauge cutter302. The passageways314can be capillary holes that draw the condensate304from the pool312of condensate into the condensate collection chamber318. Within the condensate collection chamber318, the collected condensate322pools in the bottom of the chamber. In some implementations, the condensate collection chamber318is formed between the surface of a removable core324and the interior walls320of the gauge cutter302. A lower seal326and an upper seal328prevent leakage of the collected condensate322out of the condensate collection chamber318. The lower seal326and upper seal328also prevent contamination of the collected condensate322by other fluids present in the wellbore. Since the gauge cutter302is the first tool run in the wellbore300during an intervention, the probability of obtaining a sample of condensate304is higher than for subsequent intervention tool runs because the well and condensate have not been disturbed.

In some implementations, the openings of the passageways314can become blocked by solid debris from the interior walls310of the wellbore300. Multiple passageways can be provided in the body of the gauge cutter302to increase the likelihood of sampling condensate304in the wellbore300. After retrieval of the gauge cutter302from the wellbore300, debris blocking the passageways314can be removed and analyzed to provide additional insight into the behavior of the well or reservoir.

FIG.7Aillustrates a cross section of a gauge cutter350removing solid debris352from the interior walls354of a wellbore356. Solid debris352(e.g., scale and paraffin) can accumulate on the interior walls354of the wellbore356decreasing the internal diameter358of the wellbore356. A function of the gauge cutter350is to define a known passage diameter within the wellbore356. In the event of the formation of scale357, the gauge cutter350can be forced through the scale357cutting the known passage diameter (e.g., the external diameter360of the gauge cutter). As the gauge cutter350is moved in a downhole direction362(e.g., RIH), the cutter blade364scrapes, cuts, and/or dislodges the solid debris352forming a clear path through the wellbore356of the diameter360of the gauge cutter350. The solid debris352that is removed from the wellbore356and fluid365within the wellbore356can move in an uphole direction relative to the gauge cutter350. The solid debris352and fluid can pass through the open aperture366in the downhole end368of the removable core370and central recess372of the gauge cutter350. The solid debris352and fluid can exit the central recess372through the large openings374in the uphole portion376of the gauge cutter350bypassing the solid debris collection chamber378. In this scenario the wiper blade379installed around the external diameter360of the gauge cutter350can fold backwards (e.g., in an uphole direction) providing a low resistance to pushing the gauge cutter350through the scale deposits on the interior walls354of the wellbore356during RIH operations. The gauge cutter350can simultaneously collect condensate samples as discussed with reference toFIG.6.

Turning back to method250inFIG.5, the gauge cutter can be moved in an uphole direction, for example, while being pulled out of the hole (POOH) (258). The gauge cutter can collect samples of solid debris in a solids collection chamber of the gauge cutter (260). For example, in gauge cutter100, solid debris can be collected in the solids collection chamber146formed by the annular space140between the removable core130and the interior walls116of the gauge cutter. The solid debris collection chamber collects a small portion of the solid debris within the wellbore. For example, the solid collection chamber can collect 50 grams to 1000 grams of solid debris. The amount of solid debris collected depends on the volume of the solid debris collection chamber. For example, the solid debris collection chamber can have a volume of 0.3 L to 1 L. Other solid debris collection chambers can have other volumes (e.g., a volume of 0.1 L to 1.5 L).

Samples collected in the wellbore can be removed from the gauge cutter by removing the solid debris collection chamber and the condensate collection chamber from the gauge cutter (262). In some implementations, the collected samples are packaged for transportation to a laboratory facility where further analysis and measurements are performed. In some implementations, analysis and measurements of the collected samples can be performed at the well site.

Example analysis that can be performed on the collected samples include separating liquid hydrocarbons from water mechanically (e.g., using a centrifuge) or chemically (e.g., using a demulsifier). The fraction of different long-chain alkanes like heptanes, octanes, nonanes within the liquid hydrocarbon phase can be characterized using a gas chromatograph. A detailed breakdown of the composition of liquid in the well bore can help in mitigating future flow assurance issues. For example, an operator can decide between several actions depending on the known composition of liquid in the wellbore. Example actions include applying a different choke setting at the surface to produce less liquid, deciding to inject scale inhibitors, and boosting reservoir pressure by water injection.

FIG.7Billustrates the collection of solid debris352when the gauge cutter350is pulled out of hole (POOH) (e.g., moving the gauge cutter350in an uphole direction380). Fluid365and entrained and/or suspended solid debris352enter the central recess372of the gauge cutter350through the large openings374and exit through the open aperture366in the downhole end368. A portion of the fluid382flows into the second annular space384between the interior walls386of the gauge cutter350and the removable core370. The portion of fluid382can flow into the second annular space384, through the slots388in the removable core370, and exit the central recess372through the open aperture366in the downhole end368of the gauge cutter350. Solid debris352entrained in the portion of fluid382that is larger than the width of the slots388in the removable core370can be retained in the annular space384and settle into the solid debris collection chamber378. The solid debris collection chamber378can collect solid debris352until the solid debris collection chamber is full. After filling the solid debris collection chamber378, the fluid365within the wellbore can continue to flow through the open aperture366in the removable core370. Entrained solid debris352can follow the fluid path365and exit the gauge cutter350through the open aperture366in the downhole end368.

A number of embodiments of these systems and methods have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure. Accordingly, other embodiments are within the scope of the following claims.