This disclosure relates to wellbore operations and more specifically to sealing wellbore tubing.
Hydrocarbons (e.g., petroleum, natural gas, combinations of them) entrapped in subsurface reservoirs can be raised to the surface (i.e., produced) by forming wellbores from the surface to the subsurface reservoir. A wellbore is formed through a subterranean zone (e.g., a formation, a portion of a formation, multiple formations) using a drilling assembly. After or during such wellbore formation, the well is cased and cemented. Then, production tubing is run into the wellbore from the surface to the subsurface reservoir. After forming the wellbore and installing the production tubing, well completions are installed in the wellbore (including in the production tubing). Well completions are well tools such as packers, valves, and the like, that are used to operate and control fluid flow through the wellbore. A back pressure valve (BPV) is an example of a well completion. A BPV is used to fluidically isolate a production tubing
This disclosure describes technologies relating to wellbore back pressure valve with pressure gauge.
Certain aspects of the subject matter described here can be implemented as a wellbore tool assembly. The assembly includes a back pressure valve (BPV) that can be installed at a location in a wellbore production tubing that can be installed in a wellbore. The BPV can fluidically isolate a portion of the wellbore production tubing downhole of the location from a portion of the wellbore production tubing uphole of the location. A threaded connection is attached to a downhole end of the BPV. The threaded connection includes multiple first threads. A pressure gauge is fluidically coupled to the BPV through the threaded connection. The pressure gauge can measure a pressure in the portion of the wellbore downhole of the location.
An aspect combinable with any other aspect includes the following features. The pressure gauge includes multiple second threads that can mate with the multiple first threads to form a fluidic coupling between the BPV and the pressure gauge.
An aspect combinable with any other aspect includes the following features. The multiple first threads are formed on an inner surface of the threaded connection, and the multiple second threads are formed on an outer surface of the pressure gauge.
An aspect combinable with any other aspect includes the following features. The BPV coupled to the pressure gauge can allow fluid flow from the portion of the wellbore production tubing uphole of the location to the portion of the wellbore production tubing downhole of the location, and prevent fluid flow from the portion of the wellbore production tubing downhole of the location to the portion of the wellbore production tubing uphole of the location.
An aspect combinable with any other aspect includes the following features. The pressure gauge includes an end that is coupled to the threaded connection and an opposite end. The opposite end is open to fluid flow.
An aspect combinable with any other aspect includes the following features. The pressure gauge includes a memory that can store the pressure in the portion of the wellbore downhole of the location that is measured by the pressure gauge.
An aspect combinable with any other aspect includes the following features. The threaded connection is attached to the downhole end of the BPV by metal-to-metal threads.
An aspect combinable with any other aspect includes the following features. The assembly includes a tubing hanger landing joint configured to be installed in the wellbore uphole of the wellbore production tubing. The tubing hanger landing joint can hang the wellbore production tubing. The tubing hanger landing join can receive the BPV fluidically coupled to the pressure gauge.
Certain aspects of the subject matter described in this disclosure can be implemented as a method. A threaded connection is attached to a downhole end of a BPV. A pressure gauge is fluidically coupled to the threaded connection. The BPV, fluidically coupled to the pressure gauge at a location in a wellbore production tubing, is installed in a wellbore. The BPV fluidically isolates a portion of the wellbore production tubing downhole of the location from a portion of the wellbore production tubing uphole of the location. Simultaneously with fluidically isolating, the pressure gauge measures a pressure in the portion of the wellbore production tubing downhole of the location.
An aspect combinable with any other aspect includes the following features. To attach the threaded connection to the downhole end of the BPV, a metal-to-metal threaded connection is formed between the downhole end of the BPV and the threaded connection.
An aspect combinable with any other aspect includes the following features. To fluidically couple the pressure gauge to the threaded connection, multiple first threads formed on an inner surface of the threaded connection are coupled to multiple second threads formed on an outer surface of the threaded connection.
An aspect combinable with any other aspect includes the following features. To fluidically isolate, by the BPV, the portion of the wellbore production tubing downhole of the location from the portion of the wellbore production tubing uphole of the location, the BPV allows fluid flow from the portion of the wellbore production tubing uphole of the location to the portion of the wellbore production tubing downhole of the location. In addition, the BPV prevents fluid flow from the portion of the wellbore production tubing downhole of the location to the portion of the wellbore production tubing uphole of the location.
An aspect combinable with any other aspect includes the following features. To allow the fluid flow from the portion of the wellbore production tubing uphole of the location to the portion of the wellbore production tubing downhole of the location, the BPV allows the fluid flow through a downhole end of the pressure gauge into the BPV.
An aspect combinable with any other aspect includes the following features. The wellbore is formed. A casing string is installed in the wellbore. A tubing hanger landing joint is installed in the casing string. The wellbore production tubing is hung from the tubing hanger landing joing. The BPV fluidically coupled to the pressure gauge is installed within the tubing hanger landing joint.
Certain aspects of the subject matter described here can be implemented as a wellbore tool assembly. The assembly includes a tubing hanger landing joint configured to be installed in a wellbore uphole of a wellbore production tubing. The tubing hanger landing joint can hang the wellbore production tubing. A back pressure valve-pressure gauge sub-assembly can be installed in the tubing hanger landing joint. The sub-assembly includes a BPV that can be installed at a location in a wellbore production tubing. A threaded connection is attached to a downhole end of the BPV. The threaded connection includes multiple first threads. A pressure gauge is fluidically coupled to the BPV through the threaded connection. The pressure gauge can measure a pressure in the portion of the wellbore downhole of the location while the BPV can simultaneously fluidically isolate a portion of the wellbore production tubing downhole of the location from a portion of the wellbore production tubing uphole of the location.
An aspect combinable with any other aspect includes the following features. The pressure gauge includes multiple second threads that can mate with the multiple first threads to form a fluidic coupling between the BPV and the pressure gauge.
An aspect combinable with any other aspect includes the following features. The multiple first threads are formed on an inner surface of the threaded connection and the multiple second threads are formed on an outer surface of the pressure gauge.
An aspect combinable with any other aspect includes the following features. The pressure gauge includes a memory configured to store the pressure in the portion of the wellbore downhole of the location that is measured by the pressure gauge.
An aspect combinable with any other aspect includes the following features. The assembly includes a production tree that can be installed uphole of the sub-assembly. The production tree is coupled to the BPV and configured to control fluid flow through the sub-assembly.
The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.
Like reference numbers and designations in the various drawings indicate like elements.
A BPV is a well tool that is installed in a tubing hanger to isolate production tubing. The BPV is designed to hold pressure from below to isolate well pressure downhole of a location at which the BPV is installed. The BPV is also designed to pump fluid, at a low flowrate, from uphole of the location at which the BPV is installed. As described below, the BPV is designed to set at a tubing hanger. The BPV is usually below ground level (i.e., a surface of the Earth at which the wellbore is formed) and is part of a wellhead barrier. The BPV is configured to minimize potential leak from the well with the benefit of being located inside (i.e., too far deep within) the wellbore. Consequently, the BPV is easier to retrieve compared with other well tools that are installed deeper within the wellbore and may require complex retrieval operations. The BPV can be used for either short term shut-ins of the wellbore or for longer term suspensions of wellbore operations. If an incident occurs at the wellhead tree valves, the BPV can still hold pressure from below and prevent leakage from the wellbore.
A pressure gauge is a well tool that is used to monitor wellbore pressure, in particular, at locations at which a seal or a fluidic isolation is created. Pressure measured by the pressure gauge can be used by well operators in different phases of wellbore operations including production, injection, shut-in conditions, and the like. Thus, the pressure gauge allows wellbore operators to evaluate subsurface well data. Pressure gauges can include built-in memories (e.g., computer-readable processors and memory), and can be run into the wellbore to record measured pressure and to store the measured pressure in the built-in memories. Examples of other gauges that can be used in place of pressure gauges include temperature gauges that can measure wellbore temperatures and combination gauges that can measure wellbore pressures and temperatures.
This disclosure describes a sub-assembly that includes a BPV to which a pressure gauge (or a temperature gauge or a pressure and temperature gauge) is mounted. The sub-assembly can be used to seal and fluidically isolate a wellbore production string. While sealing and fluidically isolating the wellbore production string, the sub-assembly can simultaneously and continuously measure wellbore properties (pressure or temperature or both) in the fluidically isolated portion of the wellbore production string. The measured wellbore properties can either be stored in memories onboard the gauge or can be wirelessly transmitted to a surface of the wellbore.
The BPV-pressure gauge sub-assembly described in this disclosure can be implemented to perform wellbore monitoring operations that are an important aspect of oil and gas wellbore operations. For example, when performing a diagnostic injection test for evaluation of subsurface reservoir behavior of the subterranean zone, small volume (e.g., 10-30 barrels) of water-based fluid can be pumped or injected at low rate into the wellbore. The pumping can then be stopped and the pressure response over time monitored (e.g., for 1-10 days) to evaluate reservoir properties and behavior or tightness (e.g., frac gradient, minimal in-situ stress, fracture closure pressure, reservoir permeability, etc.). The sub-assembly described in this disclosure can be implemented to monitor the pressure response over time. Because the sub-assembly is installed within the wellbore (or the wellhead), as opposed to outside the wellbore (or the wellhead), negative impact on pressure measurements due to day and night temperature changes can be minimized or avoided. The need to install production trees on top of the wellbore to record the pressure from surface-installed pressure gauges can also be avoided by using the sub-assembly described here. The risk of leaks associated with surface-installed equipment can also be reduced by implementing the sub-assembly described here, which is installed inside the wellbore. In addition, the sub-assembly described here can simultaneously and continuously perform the dual function of sealing the wellbore production string and measuring pressure (or other well properties) in the location downhole of the sub-assembly.
A threaded connection 110 is attached to the downhole end 108 of the BPV 102. The threaded connection 110 can be a tubular cylindrical member that includes threads (e.g., metal threads) formed on an outer surface or an inner surface or both of the threaded connection 110 to be coupled to the BPV 102 and to the pressure gauge 104, as described later. To couple to the downhole end 108 of the BPV 102, a universal thread profile can be formed on the downhole end 108 of the BPV 102. Metal-to-metal thread connection can be formed between an uphole end 112 the thread profile formed on the downhole end 108 of the BPV 102 and the thread profile formed on the threaded connection 110. The thread profile can extend along an entire length of the threaded connection 110 to connect a downhole end 114 of the threaded connection 110 to other wellbore tools as described below. In some implementations, the thread profile formed at the uphole end 112 can be different from that formed at the downhole end 114 of the threaded connection 110. The threaded connection 110 can be made of a material that can withstand downhole conditions including high temperatures and pressure, and that can maintain a seal formed by the BPV 102 with the wellbore production tubing to fluidically isolate the portion of the wellbore production tubing downhole of the sub-assembly 100 from the portion of the wellbore production tubing uphole of the sub-assembly 100. The threaded connection 110 can help easily and practically connect the BPV 102 and the pressure gauge 104. The threaded connection 110 can be rated to support the weight of the pressure gauge 104. The pressure gauge 104, which includes memory for storing the data, can weight between 500 g and 1000 g. The threaded connection 110 can also reduce vibration during production or installation.
The pressure gauge 104 is fluidically coupled to the BPV 102 through the threaded connection 110. To do so, a thread profile can be formed on or attached to an uphole end of the pressure gauge 104. The thread profile on the pressure gauge 104 can be configured to be received by and mate with the thread profile of the threaded connection 110. In some implementations, the thread profile on the pressure gauge 104 can be formed on an outer surface, and the thread profile of the threaded connection 110 can be formed on an inner surface. In some implementations, the thread profile on the pressure gauge 104 can be formed on an inner surface, and the thread profile of the threaded connection 110 can be formed on an outer surface. The thread profiles can be constructed such that, when engaged, the interface between the threaded connection 110 and the pressure gauge 104 maintains a fluidic isolation of the portion of the wellbore tubing string downhole of the sub-assembly 100. For example, the thread profiles can be metal-to-metal threads.
The pressure gauge 104 is configured to measure a pressure in the portion of the wellbore downhole of the location at which the sub-assembly 100 is installed in the wellbore production string. In some implementations, the pressure gauge 104 can be replaced with a temperature or a combined pressure/temperature gauge or another gauge or sensor that can measure other wellbore properties. The pressure gauge 104 can be an electronic pressure gauge with an onboard memory 116 that is configured to store the pressure sensed by the pressure gauge 104. The pressure values stored on the onboard memory 116 can be transferred to a computer system when the sub-assembly 100 is retrieved after use.
The sub-assembly 100 permits fluid flow in one direction (specifically, the uphole direction) and prevents fluid flow in the opposite direction (specifically, the downhole direction). The downhole end 118 of the pressure gauge 104 is open to fluid flow through the sub-assembly 100 in the uphole direction. However, because the BPV 102 prevents fluid flow in the uphole direction, fluid downhole of the location at which the sub-assembly 100 is installed cannot flow to the surface of the wellbore. In contrast, fluid can be flowed from a surface of the wellbore in the downhole direction through the BPV 102 and the pressure gauge 104.
Different wellbore completions can be installed in the wellbore production string 314 to produce the hydrocarbons. For ease of illustration, only the sub-assembly 100 and a production tree 318 are schematically shown in
Implementations of the sub-assembly 100 can be implemented using standard Cameron type H BPV outer thread to install the sub-assembly 100 in the tubing hanger joint 200. The sub-assembly 100 described here can record well properties including temperature, pressure, combinations of them, or other well properties using appropriate gauges/sensors while the wellbore production tubing is fluidically isolated with the BPV. The sub-assembly 100 can work when all wellhead valves including those in the production tree are in closed positions. The sub-assembly 100 can allow grease and integrity test for wellhead gate valves during fluidic isolation and pressure monitoring. Implementing the sub-assembly 100 does not require any changes to the tubing hanger. The tubing hanger can be installed with the same BPV profile. Deploying the sub-assembly 100 does not require any kind of slickline or wireline operation for installation or removal from the wellbore. The sub-assembly 100 can be installed with any industry standard BPV lubricator, and can be installed or removed under pressure using the BPV lubricator.
Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims.