Method for determining outlet configuration of liner tube

Abstract

A method for determining an outlet configuration of a liner tube (104) usable for stimulation of a reservoir (102) is disclosed. The method may include a step a of obtaining a desired fluid outflow distribution along one or more sections (110a-110b) of the reservoir (102), each section (110a-110b) corresponding to a portion (112a-112b) of the liner (104). The method may include a step b of determining a number of outlets for each portion (112a-112b) of the liner tube (104) as a function of a desired fluid outflow distribution (Q), a predetermined outlet size, and a difference between annulus pressure and liner tube pressure within the portion (112a-112b). The method may comprise a step c of evaluating, for each portion (112a-112b), whether an exit distribution satisfies one or more exit distance constraints within the portion (112a-112b), according to the number of exits having a predetermined exit size. The method may comprise a step d of repeating steps b and c for the at least one portion (112a-112b) with the adjusted outlet size as a predetermined outlet size if the outlet distribution of the at least one portion (112a-112b) does not satisfy one or more outlet distance constraints. In addition, a corresponding data processing apparatus, computer program and manufacturing method are disclosed.

Description

Technical Field

[0001] The present disclosure relates generally to the field of reservoir stimulation and, more particularly, to techniques for designing liner completions. Certain embodiments may provide methods for determining an outlet configuration of a liner that may be used to stimulate a reservoir (e.g., oil, water, and / or gas). Background Art

[0002] Long horizontal wells are key to improving sweep efficiency and hydrocarbon recovery while minimizing field development resources. Optimal well productivity requires effective stimulation, hydraulic fracturing, or matrix acid stimulation. Traditionally, a complicating factor in matrix acid stimulation treatments has been poor control of acid placement along the reservoir section. Limited entry liner (LEL) lower completions address the shortcomings of conventional stimulation techniques. The LEL includes several unevenly spaced outlets (e.g., holes) with the goal of evenly distributing the fluid (e.g., acid) along the reservoir section to be stimulated. Therefore, an optimal outlet spacing configuration is necessary to ensure that the fluid is distributed at a user-specified coverage rate (e.g., defined as barrels of acid per foot of reservoir section).

[0003] In the past, determining the outlet spacing configuration has been done in an iterative manner, primarily by solving the corresponding flow equations using corresponding optimization techniques.

[0004] For example, U.S. patent application US2009 / 294122 A1 discloses a method for simulating fluid transport in a system for increasing production of a well in a material formation of a resource reservoir. The system includes a conduit element arranged in the well, the conduit element including a conduit wall, the conduit wall including one or more openings for discharging fluid into the material formation surrounding the conduit element, and the method includes establishing and numerically processing a transport model for fluid transport inside the conduit element. The transport model also includes a fluid transport model in a predetermined space around the conduit element.

[0005] However, a major drawback of these methods is their computational complexity and the amount of computing resources required during execution, which is at least partially caused by the large number of iterations and iterative loops. Therefore, it is an object of the present disclosure to provide an improved method for determining the outlet configuration of a liner, thereby at least partially overcoming the above-mentioned drawbacks of the prior art. Summary of the Invention

[0006] This object is achieved by the subject matter defined in the independent claim. Advantageous developments of the disclosed embodiments are defined in the dependent claims as well as in the description and the drawings.

[0007] One aspect of the present disclosure relates to a method for determining an outlet configuration for a liner that can be used to stimulate a reservoir. The method may include the step of a) obtaining a desired fluid outflow distribution for one or more sections along the reservoir, each section corresponding to a section of the liner. The method may include the step of b) determining a number of outlets for each section of the liner based on the desired fluid outflow distribution, predetermined outlet sizes, and a difference between annular pressure and liner pressure within the section. The method may include the step of c) evaluating, for each section, whether the outlet distribution satisfies one or more outlet distance constraints within the section based on the number of outlets having the predetermined outlet sizes. The method may include the step of d) repeating steps b) and c) for the at least one section with the adjusted outlet size as the predetermined outlet size if the outlet distribution for at least one section does not satisfy the one or more outlet distance constraints.

[0008] Compared to prior art methods, the outlet configuration determined in this manner achieves a desired fluid outflow distribution while requiring fewer computational resources. This is primarily due to the inventors' discovery that by predetermining the outlet sizes and using the desired fluid outflow distribution and the pressure differential between the annulus and the liner, the number of outlets required to achieve the corresponding distribution can be determined in a deterministic manner (i.e., directly solved without optimization iterations).

[0009] Thus, throughout this disclosure, the term "determining" with respect to the number of outlets may be defined as a step that does not require an iterative process to determine the determination of the number of outlets. Conversely, "determining" may be defined as a step that determines the number of outlets without performing iterations to obtain the number of outlets. Thus, the step of determining with respect to the number of outlets may be distinguished from other method steps, such as "calculating" and / or "deriving" and / or "estimating," in that these steps may require iterations to obtain the corresponding results (e.g., calculating the flow rate using the number of outlets may include optimizing an objective function that requires one or more iterations).

[0010] Although the present aspect is explained with respect to determining the outlet configuration of a liner that can be used to stimulate a reservoir (e.g., oil, water and / or gas), the methods according to aspects of the present disclosure are also applicable to determining the outlet configuration of a liner that is used to stimulate other types of reservoirs, such as aquifers, or the like, or the outlet configuration of a liner deployed in a reservoir that does not require stimulation (i.e., the liner can also be used without stimulating the reservoir).

[0011] According to another aspect of the present disclosure, the method may include the step of deriving an annulus portion velocity and a liner portion velocity for each portion of the liner based on an expected fluid outflow distribution along one or more sections of the reservoir. The method may also include the step of estimating the line pressure based at least in part on the derived liner portion velocity and / or estimating the annulus pressure based at least in part on the derived annulus portion velocity.

[0012] The fact that the desired outflow profile is known allows the derivation of corresponding partial rates based on which the corresponding line pressure and / or annulus pressure can be estimated. Thus, by using the desired fluid outflow profile, the partial rates can be efficiently calculated without the need for additional optimization iterations.

[0013] According to another aspect of the present disclosure, each segment can be associated with a desired segment acid coverage and a segment length.An annulus portion rate and a liner portion rate can be derived for the segment based at least in part on the desired segment acid coverage and segment length for the segment.

[0014] Utilizing the expected coverage and the corresponding length of the segments allows for accurate calculation of the corresponding partial rates.

[0015] According to another aspect of the present disclosure, estimating the liner pressure may include calculating, for each pair of adjacent sections, a pressure difference between a pair of adjacent sections.

[0016] By determining the pressure differential between adjacent sections of the liner, the overall liner pressure can be accurately estimated, thereby improving the manner in which the number of outlets is determined, and therefore the outlet configuration of the liner.

[0017] According to another aspect of the present disclosure, calculating the pressure difference between a pair of adjacent sections may include calculating a friction pressure based at least in part on a friction factor, particularly a Fanning friction factor, a diameter, a pipe length, a velocity, and / or a fluid density. The diameter may include a liner diameter and / or an outlet diameter. The pipe length may represent a total pipe length L, and the pipe may include a plurality of segments, each having a segment length L. i , and wherein the total pipeline length L is equal to the lengths L of all segments in the plurality of segments i The harmony.

[0018] It is found that the pressure difference between a pair of adjacent parts is equal to the friction pressure. Therefore, calculating the friction pressure is an easily calculable way to calculate the pressure difference between adjacent parts.

[0019] According to another aspect of the present disclosure, the estimated annular pressure within each section may also be based on the pressure within the reservoir, the tubing length L, the viscosity μ, the formation volume factor B, the permeability k, the initial skin factor S, and / or factors depending on the boundary conditions of the reservoir, in particular the well type such as a vertical well or a horizontal well. The pressure within the reservoir may be denoted as P 储层 The pressure within the reservoir may represent the average reservoir pressure of the discharge area surrounding the well.

[0020] It was found that the annular pressure within each section can be derived based on equations / relationships including the above factors. Since these factors are previously known (eg, obtained by performing corresponding measurements), the annular pressure can be estimated without expensive computational operations.

[0021] According to another aspect of the present disclosure, one or more outlet distance constraints may include: the distance between adjacent outlets of a section does not exceed a predetermined upper threshold (e.g., 100 ft), the distance between adjacent outlets of a section exceeds a predetermined lower threshold (e.g., 25 ft), the outlet size is within a predetermined minimum and maximum range (e.g., 2 mm to 8 mm or 3 mm to 4 mm), and / or the outlet spacing variation does not exceed a predetermined value (e.g., 3), wherein the outlet spacing variation is the ratio of the maximum distance between two outlets in a section to the minimum distance between two outlets in the section.

[0022] In this way, the determined outlet distribution can be evaluated efficiently. Thus, it is now possible to verify whether the number of determined outlets is sufficient.

[0023] According to another aspect of the present disclosure, the adjusted outlet size may include a reduced outlet size if the distance between adjacent outlets of the portion exceeds a predetermined upper threshold, or the adjusted outlet size may include an increased outlet size if the distance between adjacent outlets of the portion is below a predetermined lower threshold.

[0024] Adjusting the outlet size results in a change in the value of the predetermined outlet size, and the number of outlets is determined based on this change in value. Although this may result in the step of determining the number of outlets being re-executed, the inventors have discovered that this re-execution of the deterministic determination of the number of outlets can be performed more efficiently than with optimization algorithms known in the prior art.

[0025] According to another aspect of the present disclosure, the method may further include using the number of outlets to calculate a flow rate, wellhead pressure, and / or acid coverage that satisfies a set of predetermined stimulation constraints. Alternatively, in the case of using a liner without stimulation, the method may further include using the number of outlets to calculate a flow rate, wellhead pressure, and / or coverage that satisfies a set of predetermined constraints.

[0026] In this way, a configuration of the liner is determined which minimizes the operating time and ensures the best possible ejection effect of the wormhole propagation.

[0027] According to another aspect of the present disclosure, determining flow rate, wellhead pressure, and / or coverage (e.g., acid coverage if the liner is being stimulated) can be accomplished by optimizing the values of flow rate, wellhead pressure, and / or coverage (e.g., acid coverage) using, inter alia, an objective function. Flow rate can be prioritized over wellhead pressure and / or coverage (e.g., acid coverage).

[0028] According to another aspect of the present disclosure, the optimization may include setting an initial value (eg, 0.25 bbl / min) as a value for the flow rate and / or setting an initial value (eg, 1000 psia) as a value for the wellhead pressure.

[0029] In this way, the convergence of the objective function is improved, which allows the optimization to stop earlier.

[0030] According to another aspect of the present disclosure, a set of predetermined (stimulation) constraints may include the annulus pressure along a predetermined section of a portion of one or more sections not exceeding the fracturing pressure along a predetermined section of the portion, preferably, wherein the section is located on the annulus side of the lower completion of the liner, and / or the wellhead pressure does not exceed a predetermined threshold, and / or the flow rate does not exceed the maximum rated capacity of the corresponding pump, and / or the injection velocity of the fluid entering the reservoir exceeds a predetermined wormhole threshold, and / or the dose provided (e.g., acid dose) exceeds the minimum amount of dose required for wormhole penetration and skin reduction (e.g., acid dose).

[0031] In this way, a configuration of the liner is determined which minimizes the operating time and ensures the best possible ejection effect of the wormhole propagation.

[0032] According to another aspect of the present disclosure, the method may further include performing a feasibility check on a configuration of the liner including an outlet profile provided for each of the one or more sections based on a set of configuration constraints.

[0033] In this way, given the actual hardware conditions at the reservoir (eg, the number of pipe connections on the drilling rig, etc.), it can be determined whether it is feasible to construct the liner according to the set outlet distribution.

[0034] According to another aspect of the present disclosure, the method may further include determining that the feasibility check on the configuration is negative, and repeating steps b and / or c for at least one of the one or more sections with the adjusted outlet size as the predetermined outlet size.

[0035] Thus, liner construction presents a trade-off between optimal outlet configuration and achieving a manufactured liner for production or injection within the reservoir.

[0036] According to another aspect of the present disclosure, the method may include the step of setting an outlet distribution for each section that satisfies one or more outlet distance constraints. Setting may include generating a display of one or more visualizations associated with the configuration of the liner including the one or more sections.

[0037] Thus, once the outlet distribution of each section is determined, the outlet distribution of each section that satisfies the constraints can, for example, be stored and thus used to determine the overall outlet configuration.The corresponding visualization can allow a user (eg, a petroleum engineer) to monitor the process in a transparent manner.

[0038] According to another aspect of the present disclosure, the method may further comprise issuing a notification, in particular a sign displayed on a display, whenever a constraint is not satisfied.

[0039] In this way, the user can evaluate the notification and assess whether the non-satisfaction of the constraints is acceptable for the current task at hand, or simply monitor the progress of determining the overall outlet configuration of the liner.

[0040] According to another aspect of the present disclosure, the method may further include segmenting the reservoir along the liner by applying one or more packers, particularly swellable packers, to obtain one or more sections of the reservoir.

[0041] This allows for zonal isolation of the reservoir along the liner.

[0042] According to another aspect of the present disclosure, the liner may be a limited access liner.

[0043] According to another aspect of the present disclosure, the method may further include constructing and / or manufacturing a liner for stimulating the reservoir.

[0044] According to another aspect of the present disclosure, stimulating a reservoir may include distributing a fluid, particularly an acid, along one or more sections of the reservoir.

[0045] According to another aspect of the present disclosure, determining the outlet configuration of the liner can include determining an optimal outlet spacing. The optimal outlet spacing can include the number of outlets along the liner, the size of the outlets along the liner, and / or the location of the outlets along the liner. The outlets can be unequally spaced or equally spaced.

[0046] According to another aspect of the present disclosure, the outlet may be an opening such as a hole.

[0047] According to another aspect of the present disclosure, the iterative steps may be performed until the outlet distribution of each portion satisfies one or more outlet distance constraints.

[0048] Another aspect of the present disclosure relates to a data processing apparatus comprising means for performing the method of any of the aspects described herein.

[0049] Another aspect of the present disclosure relates to a computer program or a computer-readable medium comprising the computer program, wherein the computer program comprises instructions which, when executed by a computer, cause the computer to perform the method of any one of the aspects described herein.

[0050] Another aspect of the present disclosure relates to a method for manufacturing a liner that can be used to stimulate a reservoir. The method may include the step of determining an outlet configuration of the liner according to any of the aspects described herein. The method may include the step of arranging the outlet of the liner according to the determined outlet configuration.

[0051] By arranging the outlets according to the determined outlet configuration using methods according to aspects of the present disclosure, a desired outflow distribution is achieved that results in improved stimulation of the reservoir when using a line for stimulating the reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The present disclosure may be better understood by referring to the following drawings:

[0053] Figure 1 is a schematic overview of a liner according to an embodiment of the present disclosure.

[0054] Figure 2 is a flow chart of a method for determining an outlet configuration of a liner according to an embodiment of the present disclosure.

[0055] Figure 3 is a schematic overview of a liner completion according to an embodiment of the present disclosure.

[0056] Figures 4 to 6 are visualizations associated with the configuration of a liner according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] Hereinafter, representative embodiments illustrated in the accompanying drawings will be explained. It should be understood that the illustrated embodiments and the following description refer to examples that are not intended to limit the embodiments to one preferred embodiment.

[0058] Figure 1A schematic overview 100 of a liner 104 according to an exemplary embodiment is illustrated. The liner 104 is positioned within an annulus 106 within a reservoir 102. The reservoir 102 may include one or more segments 110a-110b, which may be achieved by positioning one or more packers 108. Each segment 110a-110b of the reservoir 102 may thus be associated with a corresponding portion 112a-112b of the liner 104. The portions 112a-112b of the liner 104 correspond to the corresponding segments 110a-110b of the reservoir due to the segmentation achieved by the packers 108. Segmentation using the packers 108 may allow for the separation of segments 110a-110b of the reservoir 102 having different reservoir pressures and / or permeabilities, and the well completion design may accommodate this. For example, section 112a of liner 104 may correspond to section 110a of reservoir 102, and section 112b of liner 104 may correspond to section 110b of reservoir 102. Thus, each section 112a-112b may provide a corresponding outflow profile within the corresponding section 110a-110b by virtue of a corresponding outlet configuration. In the illustrated example, the outlets are holes. The outlet configurations may be determined using methods according to aspects of the present disclosure. As can be seen, executing the methods may determine the corresponding outlet configurations. For example, for section 112a of liner 104, there are three holes with corresponding positioning, size, and spacing, and for section 112b of liner 104, there are six holes with corresponding positioning, size, and spacing. By applying the optimal outlet configurations, the desired fluid outflow profile is achieved while satisfying the corresponding constraints.

[0059] By utilizing a liner 104 with a corresponding outlet configuration, fluid (e.g., acid) is forced from the surface through the production tubing without the need for coil tubing and enters the liner 104 from the left side. When the fluid reaches the first hole in section 112a, the pressure drop across the hole is so high that only a small portion of the fluid exits the liner through that hole. The remaining fluid continues along the liner 104 until it reaches the next hole, where the same process is repeated. The optimal outlet configuration determined using the methods according to aspects of the present disclosure ensures that the fluid is distributed according to a desired fluid outflow rate distribution (e.g., a user-specified acid coverage, which is defined as barrels of acid per foot of reservoir section). Therefore, constructing or manufacturing the liner 104 using the methods according to aspects of the present disclosure and using the liner 104 to stimulate the reservoir 102 will result in the distribution of fluid according to the desired fluid outflow rate distribution.

[0060] Figure 2A flow chart is illustrated of a method 200 for determining an outlet configuration for a liner 104 that can be used to stimulate an oil, water, and / or gas reservoir 102 according to an exemplary embodiment. The method 200 may include a step 202 of obtaining a desired fluid outflow distribution for one or more sections 110a-110b along the reservoir 102, each section 110a-110b corresponding to a section 112a-112b of the liner 104. The method 200 may include a step 204 of determining a number of outlets for each section 112a-112b of the liner 104 based on the desired fluid outflow distribution, predetermined outlet sizes, and a difference between annular pressure and liner pressure within the sections 112a-112b. The method 200 may include a step 206 of evaluating, for each section 112a-112b, whether the outlet distribution satisfies one or more outlet distance constraints within the sections 112a-112b based on the number of outlets having the predetermined outlet sizes. Method 200 may include step 208 of repeating steps 204 and 206 for at least one portion 112a-112b with the adjusted outlet size as the predetermined outlet size if the outlet distribution of at least one portion 112a-112b does not satisfy one or more outlet distance constraints.

[0061] The method 200 may include the step of deriving an annulus portion velocity and a liner portion velocity for each portion 112a-112b of the liner 104 based on an expected fluid outflow distribution along one or more sections 110a-110b of the reservoir 102. The method 200 may also include the step of estimating the line pressure based at least in part on the derived liner portion velocity and / or estimating the annulus pressure based at least in part on the derived annulus portion velocity.

[0062] The rate can be calculated according to the following equation:

[0063] Where Q is the total fluid outflow, Q i is the fluid outflow for segment i (e.g., the desired segment acid coverage in bbl / ft), and L i is the length of segment i. Thus, the proposed invention exploits the fact that the desired fluid outflow profile is known. This means that the velocity at any point inside the liner 104 is known. The user can specify a certain desired fluid outflow profile, thereby fixing the velocity for each annulus segment and, therefore, also the velocity inside the liner 104.

[0064] Each segment 110a-110b may be associated with a desired segment acid coverage and a segment length.An annulus portion rate and a liner portion rate may be derived for a portion based at least in part on the desired segment acid coverage and segment length of the segments 110a-110b.

[0065] Estimating the liner pressure may include calculating a pressure difference between a pair of adjacent portions 1120a and 1120b for each pair of adjacent portions 112a-112b.

[0066] Calculating the pressure difference between a pair of adjacent portions 112a and 112b may include calculating a friction pressure based at least in part on a friction factor, particularly a Fanning friction factor, diameter, conduit length, velocity, and / or fluid density.

[0067] This can be done according to the following equation:

[0068] Where f is the Fanning friction factor, D is the diameter, L is the pipe length, v is the velocity, and p is the fluid density. The diameter may include the diameter of the liner and / or the diameter of the outlet. The pipe length may represent the total pipe length L, while the pipe may include multiple segments, each having a segment length L. i , and wherein the total pipeline length L is substantially equal to all segment lengths L of the plurality of segments i The harmony.

[0069] The friction pressure can be estimated by iteratively solving the following implicit equation: Where Re is the Reynolds number, defined as

[0070] The estimated annular pressure within each portion 112a-112b may also be based on the pressure within the reservoir 102, the tubing length L, the viscosity μ, the formation volume factor B, the permeability k, the initial skin factor S, and / or factors depending on the boundary conditions of the reservoir, particularly the well type such as a vertical well or a horizontal well. The pressure within the reservoir may be denoted as P 储层 The pressure within the reservoir may represent the average reservoir pressure of the discharge area surrounding the well.

[0071] The annular pressure can be estimated using the following equation:

[0072] The pD function can take various forms depending on the boundary conditions of the reservoir. For example, for a vertical well, pD can be given as p d =0.5(lnt D +0,80907), where

[0073] For example, for a horizontal well, pD can be given as in, and and

[0074] Therefore, the difference between the annulus pressure and the liner pressure can be equal to the pressure at the outlet (e.g., the orifice) and can be written as:

[0075] Among them, C D is the discharge coefficient. Therefore, the only unknowns are the number of outlets and the size of the outlets. Therefore, by fixing the predetermined outlet size, the number of outlets (n) in each section 110a to 110b can be determined using, for example, the following equation:

[0076] This number n can then be converted into an integer value that can inherently satisfy the desired fluid outflow distribution. Thus, for each portion 112a-112b of the liner 104, the determining step 204 does not require any iterations, resulting in improved / reduced complexity and, therefore, reduced consumption of computing resources.

[0077] One or more outlet distance constraints may include: the distance between adjacent outlets of sections 112a to 112b does not exceed a predetermined upper threshold (e.g., 100 ft), the distance between adjacent outlets of sections 112a to 112b exceeds a predetermined lower threshold (e.g., 25 ft), the outlet size is within a range of predetermined minimum and maximum values (e.g., 2 mm to 8 mm or 3 mm to 4 mm), and / or the outlet spacing variation does not exceed a predetermined value (e.g., 3), where the outlet spacing variation is the ratio of the maximum distance between two outlets within a section to the minimum distance between two outlets within the section.

[0078] The adjusted outlet size may include a decreased outlet size if the distance between adjacent outlets of portions 112a to 112b exceeds a predetermined upper threshold, or an increased outlet size if the distance between adjacent outlets of portions 112a to 112b is below a predetermined lower threshold.

[0079] The method 200 may also include using the number of outlets to calculate a flow rate, wellhead pressure, and / or acid coverage that satisfies a set of predetermined stimulation constraints.

[0080] Calculating the flow rate, wellhead pressure and / or acid coverage can be accomplished by specifically optimizing the values of the flow rate, wellhead pressure and / or acid coverage using an objective function. The flow rate can take precedence over the wellhead pressure and / or acid coverage. The optimization can include setting an initial value (e.g., 0.25 bbl / min) as the value of the flow rate and / or setting an initial value (e.g., 1000 psia) as the value of the wellhead pressure. The flow rate can be given priority because it minimizes the operating time and ensures the best possible injection effect for wormhole propagation. In the event that the liner pressure is not greater than the annulus pressure, the flow through the corresponding outlet may reverse and become negative. In this way, the convergence of the optimization is ensured. Evaluation of the optimization shows that full convergence typically takes less than 15 seconds.

[0081] A set of predetermined stimulation constraints may include an annular pressure along a predetermined section of the one or more sections 112a to 112b not exceeding a fracture pressure along a predetermined section of the sections 112a to 112b, preferably, wherein the section is located on the annular side 106 of the lower completion of the liner 104, and / or the wellhead pressure does not exceed a predetermined threshold, and / or the flow rate does not exceed the maximum rated capacity of the corresponding pump, and / or the injection velocity of the fluid entering the reservoir 102 exceeds a predetermined wormhole threshold, and / or the acid dosage provided exceeds the minimum acid dosage required for wormhole penetration and skin reduction. With respect to the injection velocity, 15 m / s is generally considered a reasonable minimum injection velocity.

[0082] Alternatively, where the liner is not used for production stimulation (e.g., an alternative pipeline may be used to distribute oil and / or gas (for production wells), or to inject water (for injection wells)), a set of predetermined constraints may include the annulus pressure along a predetermined section of one or more sections 112a to 112b not exceeding the fracturing pressure along a predetermined section of sections 112a to 112b, preferably, wherein the section is located on the annulus side 106 of the lower completion of the liner 104, and / or the wellhead pressure does not exceed a predetermined threshold, and / or the flow rate does not exceed the maximum rated capacity of the corresponding pump, and / or the injection velocity of the fluid entering the reservoir 102 exceeds a predetermined wormhole threshold.

[0083] The method 200 may also include performing a feasibility check on the configuration of the liner 104, including an outlet distribution configured for each of the one or more sections 112a-112b based on a set of configuration constraints. The feasibility check may involve the outlet configuration and / or the overall liner completion, such as whether the total number of connections satisfies the available pipe connections on the right side, including blank connections (i.e., connections without any outlets) and connections with outlets of a specific outlet size / diameter (e.g., 1 to 4 holes). If connections with different outlet sizes are involved, the outlet sizes of some sections of the liner may be changed to accommodate the available connections.

[0084] The method 200 may also include determining that the feasibility check on the configuration is negative, and repeating steps 204 and / or 206 for at least one of the one or more portions 112a-112b with the adjusted outlet size as the predetermined outlet size.

[0085] The method 200 may include the step of setting an outlet distribution for each portion 112a-112b that satisfies one or more outlet distance constraints. Setting may include generating a display of one or more visualizations associated with the configuration of the liner 104 including the one or more portions 112a-112b.

[0086] The method 200 may further comprise issuing a notification, in particular a flag displayed on a display, whenever a constraint is not satisfied.

[0087] The method 200 may further include segmenting the reservoir 102 by applying one or more packers 108, particularly swellable packers, along the liner 104 to obtain one or more sections 110a-b of the reservoir 102. The liner may be a limited access liner.

[0088] The method 200 may also include constructing and / or manufacturing the liner 104 for stimulating the reservoir 102. Stimulating the reservoir 102 may include distributing a fluid, particularly an acid, along one or more sections 110a-110b of the reservoir 102.

[0089] Determining the outlet configuration of the liner 104 can include determining an optimal outlet spacing. The optimal outlet spacing can include the number of outlets along the liner 104, the size of the outlets along the liner 104, and / or the location of the outlets along the liner 104. The outlets can be unequally spaced or equally spaced. The outlets can be openings such as holes or valves.

[0090] The iterative steps may be performed until the outlet distribution of each section 112a - b satisfies one or more outlet distance constraints.

[0091] Figure 3 A schematic overview 300 of a liner 104 completion according to an embodiment of the present disclosure is illustrated. In the upper portion 302, the liner 104 completion is shown separated into unitary elements. As can be seen, the liner 104 is separated into unitary elements (represented by squares). The same applies to the surrounding annulus 106 and reservoir 102. The reservoir 102 is divided into two sections using swellable packers as indicated by the gray squares. Consequently, the pipeline 104 is also divided into two corresponding sections, wherein each section includes an outlet (e.g., a choke).

[0092] In the lower portion 303, the liner 104 completion is shown separated into sections. As can be seen, the desired fluid outflow profile Q is distributed across four sections Q1 to Q4 of the reservoir 102. To this end, three corresponding packers (illustrated by gray blocks) are deployed. Consequently, each corresponding section of the liner 104 is configured with a corresponding outlet configuration. In this simplified example, each section of the liner 104 includes one outlet (e.g., a choke).

[0093] Figure 4 Illustrated are visualization views 402 - 412 associated with the configuration of the liner 102 according to an embodiment of the present disclosure.

[0094] Visualization 402 illustrates the distribution of outlet sizes (e.g., pore sizes) along segments of reservoir 102 as determined using method 200. As can be seen, in this example, reservoir 102 includes 15 segments, of which the first 7 segments have pore sizes of 3 mm and the remaining 8 segments have pore sizes of 4 mm.

[0095] Visualization 404 illustrates acid coverage along sections of reservoir 102 resulting from performing method 200. As can be seen, in this example, reservoir 102 includes 15 sections, where equal coverage of 1 bbl / ft is achieved along each section due to the outlet configuration determined using method 200.

[0096] Visualization 406 illustrates the permeability (mD) along the segments of reservoir 102 resulting from performing method 200. As can be seen, in this example, reservoir 102 includes 15 segments having an equal permeability of 0.9 mD along each segment.

[0097] The visualization 408 illustrates the fracture pressure margins (psia) along the segments of the reservoir 102 as determined using the method 200. As can be seen, in this example, the reservoir 102 includes 15 segments that have an equal fracture pressure margin of 900 psia along each segment. The margin can be defined as the fracture pressure minus the annular injection pressure.

[0098] Visualization 410 illustrates the number of outlets (e.g., the number of holes) for each section of reservoir 102 resulting from executing method 200. As can be seen, in this example, reservoir 102 includes 15 sections. The portion of liner 104 corresponding to the first section includes 10 holes. The portion of liner 104 corresponding to the second section includes 11 holes. The portion of liner 104 corresponding to the third section includes 12 holes. The portions of liner 104 corresponding to the fourth and fifth sections each include 14 holes. The portion of liner 104 corresponding to the sixth section includes 16 holes. The portion of liner 104 corresponding to the seventh section includes 17 holes. The portion of liner 104 corresponding to the eighth section includes 11 holes. The portion of liner 104 corresponding to the ninth section includes 12 holes. The portions of liner 104 corresponding to the tenth and eleventh sections each include 13 holes. The portion of the liner 104 corresponding to the twelfth section includes 14 holes. The portions of the liner 104 corresponding to the thirteenth section, the fourteenth section, and the fifteenth section each include 15 holes.

[0099] Visualization 412 illustrates the thickness (ft) along the sections of reservoir 102 resulting from performing method 200. As can be seen, in this example, reservoir 102 includes 15 sections having an equal thickness of 50 ft along each section.

[0100] Figure 5 Illustrated are visualization views 502 - 508 associated with the configuration of the liner 102 according to an embodiment of the present disclosure.

[0101] Visualization 502 illustrates the distribution of reservoir pressure (psia) along the segments of reservoir 102 determined using method 200. As can be seen, in this example, reservoir 102 includes 15 segments, wherein a Pres of 4000 psia exists in each segment. The Pwf of each segment is 5000 psia. The liner pressure in the first five segments is greater than 5000 psia, but slowly decreases to 5000 psia in the last five segments.

[0102] The visualization 504 illustrates the liner rate (bpm) along the segments of the reservoir 102 resulting from executing the method 200. As can be seen, the liner rate starts at 16 bpm at the first segment and decreases linearly to 1 bpm at the final fifteenth segment.

[0103] Visualization 506 illustrates the initial skin along a segment of reservoir 102 as determined using method 200. As can be seen, in this example, reservoir 102 includes 15 segments with an initial skin of zero along each segment.

[0104] Visualization 508 illustrates retention times (min) along segments of reservoir 102 resulting from executing method 200. As can be seen, the retention time starts at slightly over 0 min at the first segment and increases to approximately 42.5 min at the final fifteenth segment.

[0105] Figure 6 Illustrated are visualization views 602 - 608 associated with the configuration of the liner 102 according to an embodiment of the present disclosure.

[0106] Visualization 602 illustrates the distribution of outlet distances (eg, hole distance in ft) along segments of reservoir 102 as determined using method 200. As can be seen, in this example, reservoir 102 includes 15 segments.

[0107] The portion of liner 104 corresponding to the first section has a bore distance of 85 ft. The portion of liner 104 corresponding to the second section has a bore distance of 75 ft. The portion of liner 104 corresponding to the third section has a bore distance of 70 ft. The portions of liner 104 corresponding to the fourth and fifth sections have bore distances of 62 ft and 60 ft, respectively. The portion of liner 104 corresponding to the sixth section has a bore distance of 52 ft. The portion of liner 104 corresponding to the seventh section has a bore distance of 49 ft. The portion of liner 104 corresponding to the eighth section has a bore distance of 75 ft. The portion of liner 104 corresponding to the ninth section has a bore distance of 72 ft. The portions of liner 104 corresponding to the tenth and eleventh sections each have a bore distance of 65 ft. The portion of liner 104 corresponding to the twelfth section has a bore distance of 60 ft. Portions of the liner 104 corresponding to the thirteenth, fourteenth, and fifteenth sections have hole distances of 58 ft and 55 ft, respectively.

[0108] Visualization 604 illustrates injection velocity (m / s) along the segments of reservoir 102 resulting from executing method 200. As can be seen, the injection velocity starts at 40 m / s at the first segment and drops to 15 m / s at the final fifteenth segment.

[0109] Visualization 606 illustrates the pressure drop (dP) (psia) at the outlet of the segments along the reservoir 102 resulting from performing method 200. As can be seen, dP starts at approximately 200 psia at the first segment and decreases in a cubic manner to 25 psia at the final fifteenth segment.

[0110] The visualization 608 illustrates the area along the section of the reservoir 102 resulting from executing the method 200 in mm. 2 As can be seen, the hole area is 70 mm in the first section. 2 Starts and increases linearly to 190 mm at the thirteenth section 2 , then it decreases slightly in the fourteenth and fifteenth sections and increases to 180mm 2 is the largest.

[0111] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ."

[0112] Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of a corresponding method, where a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.

[0113] Embodiments of the present disclosure can be implemented on a computer system. The computer system can be a local computer device (e.g., a personal computer, a laptop computer, a tablet computer, or a mobile phone) with one or more processors and one or more storage devices, or can be a distributed computer system (e.g., a cloud computing system with one or more processors and one or more storage devices distributed in various locations, such as distributed in a local client and / or one or more remote server farms and / or a data center). The computer system can include any circuit or combination of circuits. In one embodiment, the computer system can include one or more processors that can be of any type. As used herein, a processor can refer to any type of computing circuit, such as, but not limited to, a microprocessor, a microcontroller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a graphics processor, a digital signal processor (DSP), a multi-core processor, a field programmable gate array (FPGA), or any other type of processor or processing circuit. Other types of circuits that may be included in a computer system may be custom circuits, application specific integrated circuits (ASICs), and the like, such as, for example, one or more circuits (e.g., communications circuits) for use in wireless devices such as cell phones, tablet computers, laptop computers, two-way radios, and similar electronic systems. A computer system may include one or more storage devices, which may include one or more storage elements suitable for a particular application, such as main memory in the form of random access memory (RAM), one or more hard disk drives, and / or one or more drives for handling removable media, such as compact disks (CDs), flash memory cards, digital video disks (DVDs), and the like. A computer system may also include a display device, one or more speakers, and a keyboard and / or controller, which may include a mouse, trackball, touch screen, voice recognition device, or any other device that allows a system user to input information into and receive information from the computer system.

[0114] Some or all of the method steps may be performed by (or using) a hardware device such as a processor, a microprocessor, a programmable computer or an electronic circuit. In some embodiments, some or more of the most important method steps may be performed by such a device.

[0115] Depending on certain implementation requirements, embodiments of the present disclosure may be implemented in hardware or software. The implementation may be performed using a non-transitory storage medium, such as a digital storage medium, such as a floppy disk, DVD, Blu-ray, CD, ROM, PROM, and EPROM, EEPROM, or flash memory, having electronically readable control signals stored thereon, which cooperates (or is capable of cooperating) with a programmable computer system to perform the corresponding method. Thus, the digital storage medium may be computer-readable.

[0116] Some embodiments according to the present disclosure comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0117] Generally, the embodiments of the present disclosure can be implemented as a computer program product with a program code, which, when the computer program product runs on a computer, is operable to perform one of the methods. The program code can, for example, be stored on a machine-readable carrier.

[0118] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.

[0119] In other words, an embodiment of the present disclosure is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0120] Another embodiment of the present disclosure is therefore a storage medium (or data carrier, or computer-readable medium), the storage medium comprising a computer program stored thereon, the computer program for performing one of the methods described herein when the computer program is executed by a processor. The data carrier, digital storage medium, or recorded medium is typically tangible and / or non-transitory. Another embodiment of the present disclosure is a device comprising a processor and a storage medium as described herein.

[0121] Therefore, another embodiment of the present disclosure is a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may, for example, be configured to be transmitted via a data communication connection, for example via the Internet.

[0122] A further embodiment comprises a processing device, for example a computer or a programmable logic device, configured to or adapted to perform one of the methods described herein.

[0123] A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0124] Another embodiment according to the present disclosure includes an apparatus or system configured to transmit (e.g., electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may be, for example, a computer, a mobile device, a memory device, etc. The apparatus or system may, for example, include a file server for transmitting the computer program to the receiver.

[0125] In some embodiments, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the methods described herein. In some embodiments, the field programmable gate array can cooperate with a microprocessor to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware device.

Claims

1. A computer-implemented method for determining an outlet configuration of a liner that can be used to stimulate a reservoir, the method comprising the steps of: a. obtaining a desired fluid outflow distribution along one or more sections of the reservoir, each section corresponding to a portion of the liner; b. determining the number of outlets for each section of the liner based on the desired fluid outflow distribution, the predetermined outlet size, and the difference between the annulus pressure and the liner pressure within the section; c. evaluating, for each section, whether the outlet distribution satisfies one or more outlet distance constraints within the section based on the number of outlets having the predetermined outlet size; as well as d. If the outlet distribution of at least one portion does not satisfy the one or more outlet distance constraints, repeat steps b and c for the at least one portion using the adjusted outlet size as the predetermined outlet size.

2. The method according to the preceding claim, further comprising: deriving an annulus portion rate and a liner portion rate for each portion of the liner based on a desired fluid outflow distribution along one or more sections of the reservoir; estimating a pipeline pressure based at least in part on the derived liner portion velocity; as well as An annulus pressure is estimated based at least in part on the derived annulus portion velocity.

3. The method according to the preceding claim, wherein Each segment is associated with a desired segment acid coverage and a segment length; and Wherein the annulus portion rate and the liner portion rate are derived in part based at least in part on the desired segment acid coverage of the segment and the segment length.

4. The method according to any one of claims 2 to 3, wherein: Estimating the liner pressure includes: The pressure difference between a pair of adjacent sections is calculated for each pair of adjacent sections.

5. The method according to the preceding claim, wherein Calculating the pressure difference between the pair of adjacent sections includes: The friction pressure is calculated based at least in part on a friction factor, particularly a Fanning friction factor, a diameter, a pipe length, a velocity, and / or a fluid density.

6. The method according to any one of claims 2 to 5, wherein: Estimating the annular pressure in each section is also based on the pressure in the reservoir, tubing length L, viscosity μ, B, k, S and factors depending on the boundary conditions of the reservoir, in particular the well type such as vertical or horizontal well.

7. The method according to any one of the preceding claims, wherein The one or more exit distance constraints include: The distance between adjacent exits of some of the outlets does not exceed a predetermined upper threshold, in particular 100 ft; The distance between some adjacent exits exceeds a predetermined lower threshold, in particular, 25 ft; The outlet size is within a range of predetermined minimum and maximum values, in particular 2 mm to 8 mm, in particular 3 mm to 4 mm; and / or The outlet spacing variation does not exceed a predetermined value, in particular 3, wherein the outlet spacing variation is the ratio of the maximum distance between two outlets in a section to the minimum distance between two outlets in a section.

8. The method according to the preceding claim, wherein The adjusted outlet size: including a reduced outlet size if the distance between adjacent outlets of a portion exceeds said predetermined upper threshold; or Increasing the outlet size is included in the event that the distance between adjacent outlets of a portion is below the predetermined lower threshold.

9. The method according to any one of the preceding claims, further comprising: The number of outlets is used to calculate a flow rate, wellhead pressure, and / or acid coverage that satisfies a set of predetermined stimulation constraints.

10. The method according to the preceding claim, wherein The calculation is done by optimizing the values of the flow rate, the wellhead pressure and / or the acid coverage using in particular an objective function; preferably, wherein the flow rate takes precedence over the wellhead pressure and / or the acid coverage.

11. The method according to the preceding claim, wherein The optimization also includes: Setting an initial value, in particular 0.25 bbl / min, as the flow rate value; and / or An initial value, specifically 1000 psia, is set as the value of the wellhead pressure.

12. The method according to any one of claims 9 to 11, wherein: The set of predetermined production increase constraints includes: an annulus pressure along a predetermined section of a portion of the one or more sections does not exceed a fracturing pressure along the predetermined section of the portion, preferably wherein the section is located on the annulus side of a lower completion of the liner; and / or The wellhead pressure does not exceed a predetermined threshold; and / or The flow rate does not exceed the maximum rated capacity of the corresponding pump; and / or The injection velocity of the fluid entering the reservoir exceeds a predetermined wormhole threshold; and / or The acid dosage provided exceeds the minimum amount required for wormhole penetration and cuticle reduction.

13. The method according to any one of the preceding claims, further comprising: A feasibility check of a configuration of the liner including an outlet distribution set for each of the one or more sections based on a set of configuration constraints is performed.

14. The method according to the preceding claim, further comprising: determining that a feasibility check of the configuration is negative; as well as Repeat steps b and / or c for at least one of the one or more portions using the adjusted outlet size as the predetermined outlet size.

15. The method according to any one of the preceding claims, wherein The method comprises the step of setting, for each section, an outlet distribution that satisfies the one or more outlet distance constraints; and wherein setting preferably comprises: A display of one or more visualizations associated with the configuration of the liner including the one or more portions is generated.

16. The method according to any one of the preceding claims, further comprising: Whenever a constraint is not met, a notification is issued, in particular a flag is displayed on a display.

17. The method according to any one of the preceding claims, further comprising: The reservoir is segmented along the liner by applying one or more packers, in particular swellable packers, to obtain one or more zones of the reservoir.

18. A method according to any one of the preceding claims, wherein The liner is a limited entry liner.

19. The method according to any one of the preceding claims, further comprising: A liner is constructed and / or manufactured for stimulating the reservoir.

20. The method according to any one of the preceding claims, wherein Stimulating the reservoir includes: A fluid, particularly an acid, is distributed along one or more sections of the reservoir.

21. The method according to any one of the preceding claims, wherein Determining the outlet configuration of the liner includes determining an optimal outlet spacing.

22. The method according to the preceding claim, wherein The optimal outlet spacing includes: the number of outlets along the liner; the dimensions of the outlet along the liner; and / or The location of the outlet along the liner.

23. A method according to any one of the preceding claims, wherein The outlets of the outlet distribution are unequally spaced or equally spaced; and / or Wherein, the outlet is a hole.

24. The method according to any one of claims 1 to 3, wherein: The repeated steps are performed until the outlet distribution of each section satisfies the one or more outlet distance constraints.

25. Data processing apparatus comprising means for performing the method of any preceding claim.

26. A computer program or a computer-readable medium comprising a computer program, wherein: The computer program comprises instructions which, when executed by a computer, cause the computer to perform the method of any one of the preceding claims.

27. A method for manufacturing a liner useful for stimulating a reservoir, the method comprising the steps of: Determining the outlet configuration of the liner according to any one of claims 1 to 24; as well as The outlets are arranged along the liner according to the determined outlet configuration.

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