Fracturing operation bottom hole pressure calculation method and device

Abstract

The application discloses a kind of well bottom pressure calculation method and device for fracturing construction, wherein the method comprises: comparing the cumulative liquid volume of target well at current time with the preset liquid volume corresponding to well section position, according to the comparison result of cumulative liquid volume, determine the well section position acted by cumulative liquid volume at current time;According to the cumulative liquid volume of target well at current time and the well section position acted, the liquid type, sand concentration and displacement of well section position are found in the corresponding relationship table based on the corresponding relationship table at the same time;According to the liquid type, sand concentration and displacement corresponding to well section position, the corresponding pipe string friction and liquid column static pressure are calculated;According to the casing pressure known at current time, the calculated liquid column static pressure and pipe string friction, calculate the well bottom pressure at current time.The application effectively overcomes the measurement error caused by the dynamic change lag of wellbore liquid distribution in the traditional method, significantly improves the accuracy of well bottom pressure monitoring.

Description

Technical Field

[0001] This invention relates to the field of downhole fracturing operation technology, and in particular to a method and apparatus for calculating bottom hole pressure during fracturing operations. Background Technology

[0002] This section is intended to provide background or context for the embodiments of the invention set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section.

[0003] In the field of intelligent fracturing technology, existing technologies typically employ hydraulic fracturing to increase single-well production. This method uses high-pressure fluid to drive the expansion of artificial fracture networks within the formation, significantly increasing the contact area between the wellbore and the reservoir. With the world entering an era of developing unconventional oil and gas reserves and difficult-to-access reserves, hydraulic fracturing has become a key engineering technology for exploration and development. However, traditional fracturing processes rely on experience-based decision-making, making it difficult to accurately control fracture dynamics and construction risks. In recent years, intelligent fracturing has integrated technologies such as artificial intelligence and cloud computing, driving a data-driven transformation of the process. However, its practical application requires high-precision real-time data support, with bottomhole pressure data being a crucial component.

[0004] Bottomhole pressure, the sum of various pressures acting on the bottom of the well during fracturing operations from both the surface and within the well, is a crucial basis for judging the fracture propagation status, assessing the risks of proppant injection, and optimizing fracturing parameters. In actual fracturing operations, only the wellhead pressure located at the surface is directly monitored. However, due to the influence of various factors such as the properties of the fluid within the tubing and the concentration of proppant, and because the fluid distribution within the tubing changes constantly during fracturing, a significant systematic error exists between the wellhead pressure and the bottomhole pressure. This error makes it impossible to obtain accurate bottomhole pressure data, severely impacting the safety and efficiency of the operation.

[0005] To obtain accurate bottomhole pressure data, the traditional approach is to use downhole pressure gauges for real-time monitoring. However, the application of downhole pressure gauges faces high monitoring costs and a high risk of tool jamming in multi-stage fracturing of horizontal wells, limiting their large-scale application. Existing technologies struggle to accurately determine the distribution of fluids in the wellbore and calculate the corresponding bottomhole pressure in real time, and cannot overcome the distortion problem of wellhead pressure data, resulting in inaccurate bottomhole pressure data and difficulty in reducing the cost of obtaining bottomhole pressure. Summary of the Invention

[0006] This invention provides a method for calculating bottom hole pressure during fracturing operations to improve the accuracy of bottom hole pressure data. The method includes:

[0007] The cumulative fluid volume of the target well at the current moment is compared with the preset fluid volume at the corresponding well section. Based on the comparison result of the cumulative fluid volume, the well section position affected by the cumulative fluid volume at the current moment is determined. The well section position includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is determined in advance based on the well structure and wellbore volume.

[0008] Based on the correspondence table at the same time, according to the cumulative liquid volume of the target well at the current time and the location of the affected well section, the liquid type, sand concentration and discharge rate of the well section are looked up in the correspondence table; the correspondence table is established at the same time based on the correspondence between the time series data of the translated liquid type and sand concentration, the time series data of the cumulative liquid volume and the discharge rate at the current time.

[0009] Calculate the corresponding tubing friction and hydrostatic pressure based on the fluid type, sand concentration, and discharge rate corresponding to the well section location;

[0010] Based on the known casing pressure at the current moment, calculate the hydrostatic pressure of the liquid column and the friction of the tubing, and then calculate the bottom hole pressure at the current moment.

[0011] This invention also provides a bottom-hole pressure calculation device for fracturing operations to improve the accuracy of bottom-hole pressure data. The device includes:

[0012] The well section location determination module is used to compare the cumulative fluid volume of the target well at the current moment with the preset fluid volume of the corresponding well section location. Based on the comparison result of the cumulative fluid volume, the well section location affected by the cumulative fluid volume at the current moment is determined. The well section location includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is determined in advance based on the well structure and wellbore volume.

[0013] The correspondence table query module is used to look up the liquid type, sand concentration, and discharge rate of the target well at the current time based on the correspondence table at the same time, according to the cumulative liquid volume of the target well and the location of the affected well section. The correspondence table is established at the same time based on the correspondence between the time-series data of the translated liquid type and sand concentration, the time-series data of the cumulative liquid volume, and the discharge rate at the current time.

[0014] The tubing friction and hydrostatic pressure calculation module is used to calculate the corresponding tubing friction and hydrostatic pressure based on the fluid type, sand concentration and discharge rate corresponding to the well section location.

[0015] The bottom hole pressure calculation module is used to calculate the bottom hole pressure at the current moment based on the known casing pressure, the hydrostatic pressure of the fluid column, and the friction of the tubing.

[0016] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-mentioned method for calculating bottom hole pressure during fracturing operations.

[0017] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating bottom hole pressure during fracturing operations.

[0018] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-mentioned method for calculating bottom hole pressure during fracturing operations.

[0019] In this embodiment of the invention, the cumulative fluid volume of the target well at the current moment is compared with the preset fluid volume at the corresponding well section location. Based on the comparison result of the cumulative fluid volume, the well section location affected by the cumulative fluid volume at the current moment is determined. The well section location includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is predetermined based on the well structure and wellbore volume. Based on the correspondence table at the same time, the fluid type, sand concentration, and discharge rate of the well section location are looked up in the correspondence table according to the cumulative fluid volume of the target well at the current moment and the well section location affected. The correspondence table is established at the same time based on the correspondence between the time-series data of the translated fluid type and sand concentration, the time-series data of the cumulative fluid volume, and the discharge rate at the current moment. Based on the fluid type, sand concentration, and discharge rate corresponding to the well section location, the corresponding tubing friction and hydrostatic pressure are calculated. Based on the known casing pressure at the current moment, the hydrostatic pressure and tubing friction are calculated, and the bottom hole pressure at the current moment is calculated. In the above process, the embodiments of the present invention accurately determine the well section location affected by the current cumulative liquid volume by comparing the cumulative liquid volume with the preset well section liquid volume in real time. Based on the correspondence table at the same time, the liquid type, sand concentration and discharge data corresponding to each well section location are obtained, thereby accurately calculating the tubing friction and liquid column static pressure. Combined with casing pressure, high-precision calculation of bottom hole pressure is achieved, effectively overcoming the measurement error caused by the lag in the dynamic changes of well fluid distribution in traditional methods, and significantly improving the accuracy of bottom hole pressure monitoring. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 This is a flowchart of the bottom hole pressure calculation method for fracturing operations in an embodiment of the present invention;

[0022] Figure 2 This is a flowchart illustrating the process of establishing a correspondence table in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the placement of on-site operating equipment in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the bottom hole pressure calculation device for fracturing operations in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of a computer device in an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0027] The acquisition, storage, use, and processing of data in this application all comply with the relevant provisions of national laws and regulations.

[0028] Figure 1 This is a flowchart of a method for calculating bottom hole pressure during fracturing operations according to an embodiment of the present invention. The method includes:

[0029] Step 101: Compare the cumulative fluid volume of the target well at the current moment with the preset fluid volume at the corresponding well section location. Based on the comparison result of the cumulative fluid volume, determine the well section location affected by the cumulative fluid volume at the current moment. The well section location includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is determined in advance based on the well structure and wellbore volume.

[0030] Step 102: Based on the correspondence table at the same time, according to the cumulative liquid volume of the target well at the current time and the location of the affected well section, look up the liquid type, sand concentration and discharge rate of the well section in the correspondence table; the correspondence table is established at the same time based on the correspondence between the time-series data of the translated liquid type and sand concentration, the time-series data of the cumulative liquid volume and the discharge rate at the current time.

[0031] Step 103: Calculate the corresponding tubing friction and hydrostatic pressure based on the fluid type, sand concentration, and discharge rate corresponding to the well section location.

[0032] Step 104: Calculate the hydrostatic pressure of the liquid column and the friction of the tubing based on the known casing pressure at the current moment, and calculate the bottom hole pressure at the current moment.

[0033] Each step is explained in detail below.

[0034] In step 101, the cumulative fluid volume of the target well at the current moment is compared with the preset fluid volume at the corresponding well section location. Based on the comparison result of the cumulative fluid volume, the well section location affected by the cumulative fluid volume at the current moment is determined. The well section location includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is determined in advance based on the well structure and wellbore volume.

[0035] Figure 2 This is a flowchart illustrating the process of establishing a correspondence table in an embodiment of the present invention. In one embodiment, before looking up the liquid type, sand concentration, and discharge rate of the well section in the correspondence table based on the cumulative liquid volume of the target well at the current time and the location of the affected well section, the process further includes:

[0036] Step 201: Obtain the known wellbore volume and surface volume, and collect the cumulative liquid volume time series data, liquid type time series data, sand concentration time series data and current discharge rate of the target well in real time;

[0037] Step 202: Use the ratio between the ground volume and the discharge volume at the current moment as the translation time at the current moment. Based on the translation time at the current moment, shift the timestamps of the liquid type time series data and the sand concentration time series data forward.

[0038] Step 203: Establish a correspondence table between the translated liquid type time series data, sand concentration time series data, cumulative liquid volume time series data, and current discharge volume at the same time.

[0039] In step 102, based on the correspondence table at the same time, the liquid type, sand concentration and discharge rate of the well section at the current time are looked up in the correspondence table according to the cumulative liquid volume of the target well and the location of the affected well section. The correspondence table is established at the same time based on the correspondence between the time-series data of the translated liquid type, the time-series data of the sand concentration, the time-series data of the cumulative liquid volume and the discharge rate at the current time.

[0040] Figure 3 This is a schematic diagram of the on-site operation equipment layout in an embodiment of the present invention. In a specific embodiment, the impact of ground volume on fluid type switching and proppant concentration on bottom hole pressure has a lag effect. For example... Figure 3As shown, during fracturing operations, the switching of fluid type and real-time measurement of proppant concentration occur at the mixing truck location. From the time the mixing truck discharges until the fluid begins to enter the wellhead, there exists a space within the high and low pressure manifolds and pump truck; this is referred to as the surface volume in engineering operations. In unconventional fracturing operations, due to high displacement, numerous pipelines, and pump trucks, the surface volume can reach over 10 cubic meters. Therefore, when the properties of the surface fluid or the proppant concentration changes, a certain amount of time (surface volume / displacement) is required before it enters the wellbore, affecting the construction pressure within the wellbore. However, the construction pressure is measured on the high-pressure pipeline near the wellhead, directly reflecting the real-time pressure changes within the wellbore. Therefore, the fracturing construction curve measured at the surface should first be shifted backward by (surface volume / displacement) time for proppant concentration and fluid type, and then combined with the wellhead construction pressure to calculate the bottomhole construction pressure.

[0041] By introducing surface volume and determining the translation time through the above steps, and correcting the wellhead pressure, the problem of data lag in fluid type and proppant concentration caused by surface pipelines and pump truck volume during fracturing operations is effectively solved, thus significantly improving the real-time performance and accuracy of bottomhole pressure calculation. By establishing a dynamic correspondence table between cumulative fluid volume and well section location, the fluid parameters measured by the sand-mixing truck are translated over time according to "surface volume / discharge rate," ensuring precise matching between wellhead pressure data and the actual fluid properties entering the wellbore. This eliminates pressure response deviations caused by data asynchrony in traditional methods, reflecting the true distribution of fluid within the wellbore in real time, and providing a more reliable basis for bottomhole pressure prediction and control during fracturing operations.

[0042] In step 103, the corresponding tubing friction and hydrostatic pressure are calculated based on the fluid type, sand concentration, and discharge rate corresponding to the well section location.

[0043] In one embodiment, the corresponding tubing friction and hydrostatic pressure are calculated based on the fluid type, sand concentration, and discharge rate corresponding to the well section location, including:

[0044] When the liquid type is clean water, calculate the tubing friction and hydrostatic pressure of the clean water column based on the clean water discharge rate, tubing inner diameter, and the length of the clean water section in the tubing.

[0045] When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated based on the guar gum solution discharge rate, tubing inner diameter, liquid section length of the guar gum solution in the tubing, and proppant concentration in the guar gum solution; the proppant concentration in the guar gum solution is determined based on the sand concentration of the guar gum solution; the tubing friction of the guar gum solution is calculated based on the product of the drag reduction ratio of the guar gum solution and the tubing friction of the clear water solution.

[0046] When the liquid type is slickwater, the drag reduction ratio of slickwater is calculated based on the difference between the drag reduction ratio of sand-free guar gum solution and the drag reduction ratio of sand-containing guar gum solution with sand. The tubing friction of slickwater is calculated based on the product of the drag reduction ratio of slickwater and the tubing friction of clean water.

[0047] In specific embodiments, the bottom hole pressure is closely related to the concentration of the sand-carrying fluid injected into the wellbore. Clearly, the higher the sand concentration in the sand-carrying fluid, the greater the pressure generated by the liquid column within the wellbore. In addition, the properties of the sand particles also have a significant impact on the bottom hole pressure. Sand volume density and apparent density are two important indicators for measuring sand particles. Volume density, also known as true density, refers to the mass of a unit volume of material (excluding the volume of pores within particles and the volume of voids between particles) under specified conditions. Apparent density, also known as apparent volume, refers to the mass of a unit volume of material in its natural state (including the volume of solid material and the volume of closed pores, but excluding the volume of voids between particles). Generally, because the calculated volume of apparent density includes closed pores within the particles, while the calculated volume of volume density is the actual solid volume of the sand, the value of volume density is usually greater than that of apparent density.

[0048] Calculating the static pressure generated by the wellbore fluid column, and calculating the cumulative volume of the sand-carrying fluid, requires treating each second of data within the wellbore as a differential unit. The calculation is then performed based on the sand concentration and depth at the corresponding moment. Finally, the pressure generated by all data segments within the wellbore is integrated and summed. The following is the method for calculating the static pressure of the wellbore fluid column:

[0049]

[0050] Among them, P 静 From t0 to t n The static pressure of the liquid column during the time period. From t0 to t n The hydrostatic pressure of the liquid column at any given time. For sand concentration, The density of the sand body, For the density of the liquid, denoted as the vertical depth difference of the wellbore, and g as the acceleration due to gravity.

[0051] In one embodiment, when the liquid type is clean water, the tubing friction and hydrostatic pressure of the clean water are calculated based on the clean water discharge rate, the tubing inner diameter, and the length of the clean water section within the tubing, including:

[0052] Calculate the tubular friction of clear water using the following formula:

[0053]

[0054] in, Let Q be the frictional resistance of the tubing for clean water, D be the inner diameter of the tubing, and L be the length of the liquid section of the clean water within the tubing.

[0055] In one embodiment, when the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated based on the guar gum solution discharge rate, column inner diameter, liquid section length of the guar gum solution within the column, and proppant concentration in the guar gum solution, including:

[0056] Calculate the drag reduction ratio of the guar gum solution using the following formula:

[0057]

[0058] in, The drag reduction ratio of the guar gum solution. D is the discharge rate of the guar gum solution, and D is the inner diameter of the tubing. G represents the sand concentration of the guar gum solution, and G represents the thickener concentration.

[0059] In one embodiment, the column friction of the guar gum solution is calculated based on the product of the drag reduction ratio of the guar gum solution and the column friction of the clean water solution, including:

[0060] Calculate the column friction of the guar gum solution using the following formula:

[0061]

[0062] in, The friction of the tubing for the guar gum solution.

[0063] In a specific embodiment, 0.3 is used as the default drag reduction ratio for slickwater purification solution; the effect of proppant on the drag reduction ratio of slickwater is treated by equivalent processing according to the drag reduction ratio formula of guar gum solution, wherein a guar gum concentration of 2.4 kg / m3 is equivalent to slickwater.

[0064] In one embodiment, the drag reduction ratio of the slickwater is calculated based on the difference between the drag reduction ratio of the sand-free guar gum solution and the drag reduction ratio of the sand-containing guar gum solution, including:

[0065] Calculate the drag reduction ratio of the sand-free guar gum solution, given a sand concentration of 2.4 kg / m³. 3 The rent reduction ratio of guar gum carrying sand solution;

[0066] Calculate the drag reduction ratio of sand-free guar gum solution using the following formula:

[0067]

[0068] in, The drag reduction ratio of the sand-free guar gum solution;

[0069] The sand concentration is calculated to be 2.4 kg / m³ according to the following formula. 3The drag reduction ratio of guar gum carrying sand fluid:

[0070]

[0071] in, This represents a sand concentration of 2.4 kg / m³. 3 The drag reduction ratio of the guar gum solution;

[0072] Calculate the drag reduction ratio of slick water using the following formula:

[0073]

[0074] in, C is the drag reduction ratio of the slickwater, and C is the preset drag reduction ratio of the purified slickwater solution, which is usually 0.3.

[0075] In step 104, the bottom hole pressure is calculated based on the known casing pressure at the current moment, the calculated hydrostatic pressure of the hydraulic column, and the tubing friction. The casing pressure can be directly obtained from a surface pressure gauge.

[0076] In a specific embodiment, force analysis of the bottom hole pressure (BHP) reveals that the casing pressure applied at the wellhead, the static pressure of the fluid column inside the wellbore, and the frictional force between the proppant-carrying fluid and the wellbore are three important factors contributing to the final bottom hole pressure. Therefore, the formula for calculating the bottom hole pressure is as follows:

[0077] ;

[0078] This allows for real-time and accurate calculation of bottom hole pressure, providing reliable data support for fracturing operations and improving the safety and efficiency of the operation.

[0079] This invention also provides a bottom-hole pressure calculation device for fracturing operations, as described in the following embodiments. Since the principle by which this device solves the problem is similar to the bottom-hole pressure calculation method for fracturing operations, the implementation of this device can refer to the implementation of the bottom-hole pressure calculation method for fracturing operations; repeated details will not be elaborated further.

[0080] Figure 4 This is a schematic diagram of a bottom hole pressure calculation device for fracturing operations in an embodiment of the present invention. The device includes:

[0081] The well section location determination module 401 is used to compare the cumulative fluid volume of the target well at the current moment with the preset fluid volume of the corresponding well section location, and determine the well section location affected by the cumulative fluid volume at the current moment based on the comparison result of the cumulative fluid volume; the well section location includes the wellhead section, the wellbore section, and the bottom section; wherein, the preset fluid volume is predetermined based on the well structure and wellbore volume;

[0082] The correspondence table query module 402 is used to look up the liquid type, sand concentration, and discharge rate of the well section at the current time based on the correspondence table at the same time, according to the cumulative liquid volume of the target well and the location of the affected well section. The correspondence table is established at the same time based on the correspondence between the time-series data of the translated liquid type and sand concentration, the time-series data of the cumulative liquid volume, and the discharge rate at the current time.

[0083] The tubing friction and hydrostatic pressure calculation module 403 is used to calculate the corresponding tubing friction and hydrostatic pressure based on the fluid type, sand concentration and discharge rate corresponding to the well section location.

[0084] The bottom hole pressure calculation module 404 is used to calculate the bottom hole pressure at the current moment based on the known casing pressure, the hydrostatic pressure of the liquid column, and the friction of the tubing.

[0085] In one embodiment, a correspondence table establishment module is further included, specifically used for:

[0086] Obtain known wellbore volume and surface volume, and collect real-time cumulative liquid volume time series data, liquid type time series data, sand concentration time series data, and current discharge rate of the target well;

[0087] The ratio between ground volume and current discharge volume is used as the shift time for the current moment. Based on the shift time for the current moment, the timestamps of liquid type time series data and sand concentration time series data are shifted forward.

[0088] Establish a correspondence table between the translated liquid type time series data, sand concentration time series data, cumulative liquid volume time series data, and current discharge volume at the same time.

[0089] In one embodiment, the tubular friction and hydrostatic pressure calculation module 403 is specifically used for:

[0090] When the liquid type is clean water, calculate the tubing friction and hydrostatic pressure of the clean water column based on the clean water discharge rate, tubing inner diameter, and the length of the clean water section in the tubing.

[0091] When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated based on the guar gum solution discharge rate, tubing inner diameter, liquid section length of the guar gum solution in the tubing, and proppant concentration in the guar gum solution; the proppant concentration in the guar gum solution is determined based on the sand concentration of the guar gum solution; the tubing friction of the guar gum solution is calculated based on the product of the drag reduction ratio of the guar gum solution and the tubing friction of the clear water solution.

[0092] When the liquid type is slickwater, the drag reduction ratio of slickwater is calculated based on the difference between the drag reduction ratio of sand-free guar gum solution and the drag reduction ratio of sand-containing guar gum solution with sand. The tubing friction of slickwater is calculated based on the product of the drag reduction ratio of slickwater and the tubing friction of clean water.

[0093] In one embodiment, the tubular friction and hydrostatic pressure calculation module 403 is specifically used for:

[0094] When the liquid type is clean water, the tubing friction of clean water is calculated according to the following formula based on the water discharge rate, tubing inner diameter, and the length of the clean water section within the tubing:

[0095]

[0096] in, Let Q be the frictional resistance of the tubing for clean water, D be the inner diameter of the tubing, and L be the length of the liquid section of the clean water within the tubing.

[0097] In one embodiment, the tubular friction and hydrostatic pressure calculation module 403 is specifically used for:

[0098] When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated according to the following formula based on the guar gum solution discharge rate, column inner diameter, liquid section length of the guar gum solution in the column, and proppant concentration in the guar gum solution:

[0099]

[0100] in, The drag reduction ratio of the guar gum solution. D is the discharge rate of the guar gum solution, and D is the inner diameter of the tubing. G represents the sand concentration of the guar gum solution, and G represents the thickener concentration.

[0101] In one embodiment, the tubular friction and hydrostatic pressure calculation module 403 is specifically used for:

[0102] The column friction of guar gum solution is calculated using the following formula, based on the product of the drag reduction ratio of the guar gum solution and the column friction of the pure water solution:

[0103]

[0104] in, The friction of the tubing for the guar gum solution.

[0105] In one embodiment, the tubular friction and hydrostatic pressure calculation module 403 is specifically used for:

[0106] Calculate the drag reduction ratio of sand-free guar gum solution using the following formula:

[0107]

[0108] in, The drag reduction ratio of the sand-free guar gum solution;

[0109] The sand concentration is calculated to be 2.4 kg / m³ according to the following formula. 3 The drag reduction ratio of guar gum carrying sand fluid:

[0110]

[0111] in, This represents a sand concentration of 2.4 kg / m³. 3 The drag reduction ratio of the guar gum solution;

[0112] Based on the drag reduction ratio of sand-free guar gum solution and a sand concentration of 2.4 kg / m³ 3 The drag reduction ratio of guar gum-carrying sand fluid is calculated using the following formula:

[0113]

[0114] in, C is the drag reduction ratio of the slickwater, and C is the preset drag reduction ratio of the purified slickwater solution, which is usually 0.3.

[0115] This invention also provides a computer device. Figure 5 This is a schematic diagram of a computer device in an embodiment of the present invention. The computer device 500 includes a memory 510, a processor 520, and a computer program 530 stored in the memory 510 and executable on the processor 520. When the processor 520 executes the computer program 530, it implements the above-mentioned method for calculating the bottom hole pressure during fracturing operations.

[0116] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating bottom hole pressure during fracturing operations.

[0117] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-mentioned method for calculating bottom hole pressure during fracturing operations.

[0118] In this embodiment of the invention, the cumulative fluid volume of the target well at the current moment is compared with the preset fluid volume at the corresponding well section location. Based on the comparison result of the cumulative fluid volume, the well section location affected by the cumulative fluid volume at the current moment is determined. The well section location includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is predetermined based on the well structure and wellbore volume. Based on the correspondence table at the same time, the fluid type, sand concentration, and discharge rate of the well section location are looked up in the correspondence table according to the cumulative fluid volume of the target well at the current moment and the well section location affected. The correspondence table is established at the same time based on the correspondence between the time-series data of the translated fluid type and sand concentration, the time-series data of the cumulative fluid volume, and the discharge rate at the current moment. Based on the fluid type, sand concentration, and discharge rate corresponding to the well section location, the corresponding tubing friction and hydrostatic pressure are calculated. Based on the known casing pressure at the current moment, the hydrostatic pressure and tubing friction are calculated, and the bottom hole pressure at the current moment is calculated. In the above process, the embodiments of the present invention accurately determine the well section location affected by the current cumulative liquid volume by comparing the cumulative liquid volume with the preset well section liquid volume in real time. Based on the correspondence table at the same time, the liquid type, sand concentration and discharge data corresponding to each well section location are obtained, thereby accurately calculating the tubing friction and liquid column static pressure. Combined with casing pressure, high-precision calculation of bottom hole pressure is achieved, effectively overcoming the measurement error caused by the lag in the dynamic changes of well fluid distribution in traditional methods, and significantly improving the accuracy of bottom hole pressure monitoring.

[0119] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0120] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0121] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0122] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0123] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for calculating bottom hole pressure during fracturing operations, characterized in that, include: The cumulative fluid volume of the target well at the current moment is compared with the preset fluid volume at the corresponding well section. Based on the comparison result of the cumulative fluid volume, the well section position affected by the cumulative fluid volume at the current moment is determined. The well section position includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is determined in advance based on the well structure and wellbore volume. Based on the correspondence table at the same time, according to the cumulative liquid volume of the target well at the current time and the location of the affected well section, the liquid type, sand concentration and discharge rate of the well section are looked up in the correspondence table; the correspondence table is established at the same time based on the correspondence between the time series data of the translated liquid type and sand concentration, the time series data of the cumulative liquid volume and the discharge rate at the current time. Calculate the corresponding tubing friction and hydrostatic pressure based on the fluid type, sand concentration, and discharge rate corresponding to the well section location; Based on the known casing pressure at the current moment, calculate the hydrostatic pressure of the liquid column and the friction of the tubing string, and calculate the bottom hole pressure at the current moment. Before looking up the fluid type, sand concentration, and discharge rate of the target well in the corresponding table based on the cumulative fluid volume of the target well at the current moment and the location of the affected well section, the process also includes: Obtain known wellbore volume and surface volume, and collect real-time cumulative liquid volume time series data, liquid type time series data, sand concentration time series data, and current discharge rate of the target well; The ratio between ground volume and current discharge volume is used as the shift time for the current moment. Based on the shift time for the current moment, the timestamps of liquid type time series data and sand concentration time series data are shifted forward. Establish a correspondence table between the translated liquid type time series data, sand concentration time series data, cumulative liquid volume time series data, and current discharge volume at the same time.

2. The method as described in claim 1, characterized in that, Based on the fluid type, sand concentration, and discharge rate corresponding to the well section location, calculate the corresponding tubing friction and hydrostatic pressure, including: When the liquid type is clean water, calculate the tubing friction and hydrostatic pressure of the clean water column based on the clean water discharge rate, tubing inner diameter, and the length of the clean water section in the tubing. When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated based on the guar gum solution discharge rate, tubing inner diameter, liquid section length of the guar gum solution in the tubing, and proppant concentration in the guar gum solution; the proppant concentration in the guar gum solution is determined based on the sand concentration of the guar gum solution; the tubing friction of the guar gum solution is calculated based on the product of the drag reduction ratio of the guar gum solution and the tubing friction of the clear water solution. When the liquid type is slickwater, the drag reduction ratio of slickwater is calculated based on the difference between the drag reduction ratio of sand-free guar gum solution and the drag reduction ratio of sand-containing guar gum solution with sand. The tubing friction of slickwater is calculated based on the product of the drag reduction ratio of slickwater and the tubing friction of clean water.

3. The method as described in claim 2, characterized in that, When the liquid type is clean water, calculate the tubing friction and hydrostatic pressure of the clean water column based on the clean water discharge rate, tubing inner diameter, and the length of the clean water section within the tubing, including: Calculate the tubular friction of the clear water system using the following formula: in, Let Q be the frictional resistance of the tubing for clean water, D be the inner diameter of the tubing, and L be the length of the liquid section of the clean water within the tubing.

4. The method as described in claim 2, characterized in that, When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated based on the guar gum solution discharge rate, column inner diameter, liquid section length of the guar gum solution within the column, and proppant concentration in the guar gum solution, including: Calculate the drag reduction ratio of the guar gum solution using the following formula: in, The drag reduction ratio of the guar gum solution. This refers to the discharge volume of the guar gum solution. D The inner diameter of the tubular column, The sand concentration of the guar gum solution. G This refers to the concentration of the thickener.

5. The method as described in claim 4, characterized in that, The column friction of the guar gum solution is calculated based on the product of the drag reduction ratio of the guar gum solution and the column friction of the pure water solution, including: Calculate the column friction of the guar gum solution using the following formula: in, The friction of the tubing for the guar gum solution.

6. The method as described in claim 2, characterized in that, The drag reduction ratio of slickwater is calculated based on the difference between the drag reduction ratio of sand-free guar gum solution and the drag reduction ratio of guar gum solution containing sand and carrying sand. This includes: Calculate the drag reduction ratio of the sand-free guar gum solution, given a sand concentration of 2.4 kg / m³. 3 The rent reduction ratio of guar gum carrying sand solution; Calculate the drag reduction ratio of sand-free guar gum solution using the following formula: in, The drag reduction ratio of the sand-free guar gum solution; The sand concentration is calculated to be 2.4 kg / m³ according to the following formula. 3 The drag reduction ratio of guar gum carrying sand fluid: in, This represents a sand concentration of 2.4 kg / m³. 3 The drag reduction ratio of the guar gum solution; Calculate the drag reduction ratio of slick water using the following formula: in, C represents the drag reduction ratio of the slickwater, and C is the preset drag reduction ratio of the purified slickwater solution.

7. A bottom hole pressure calculation device for fracturing operations, characterized in that, include: The well section location determination module is used to compare the cumulative fluid volume of the target well at the current moment with the preset fluid volume of the corresponding well section location. Based on the comparison result of the cumulative fluid volume, the well section location affected by the cumulative fluid volume at the current moment is determined. The well section location includes the wellhead section, the wellbore section, and the bottom section. The preset fluid volume is determined in advance based on the well structure and wellbore volume. The correspondence table query module is used to look up the liquid type, sand concentration, and discharge rate of the target well at the current time based on the correspondence table at the same time, according to the cumulative liquid volume of the target well and the location of the affected well section. The correspondence table is established at the same time based on the correspondence between the time-series data of the translated liquid type and sand concentration, the time-series data of the cumulative liquid volume, and the discharge rate at the current time. The tubing friction and hydrostatic pressure calculation module is used to calculate the corresponding tubing friction and hydrostatic pressure based on the fluid type, sand concentration and discharge rate corresponding to the well section location. The bottom hole pressure calculation module is used to calculate the hydrostatic pressure of the fluid column and the friction of the tubing string based on the known casing pressure at the current moment, and to calculate the bottom hole pressure at the current moment. It also includes a module for creating corresponding relationship tables, specifically used for: Obtain known wellbore volume and surface volume, and collect real-time cumulative liquid volume time series data, liquid type time series data, sand concentration time series data, and current discharge rate of the target well; The ratio between ground volume and current discharge volume is used as the shift time for the current moment. Based on the shift time for the current moment, the timestamps of liquid type time series data and sand concentration time series data are shifted forward. Establish a correspondence table between the translated liquid type time series data, sand concentration time series data, cumulative liquid volume time series data, and current discharge volume at the same time.

8. The apparatus as claimed in claim 7, characterized in that, The module for calculating tubular friction and hydrostatic pressure is specifically used for: When the liquid type is clean water, calculate the tubing friction and hydrostatic pressure of the clean water column based on the clean water discharge rate, tubing inner diameter, and the length of the clean water section in the tubing. When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated based on the guar gum solution discharge rate, tubing inner diameter, liquid section length of the guar gum solution in the tubing, and proppant concentration in the guar gum solution; the proppant concentration in the guar gum solution is determined based on the sand concentration of the guar gum solution; the tubing friction of the guar gum solution is calculated based on the product of the drag reduction ratio of the guar gum solution and the tubing friction of the clear water solution. When the liquid type is slickwater, the drag reduction ratio of slickwater is calculated based on the difference between the drag reduction ratio of sand-free guar gum solution and the drag reduction ratio of sand-containing guar gum solution with sand. The tubing friction of slickwater is calculated based on the product of the drag reduction ratio of slickwater and the tubing friction of clean water.

9. The apparatus as claimed in claim 8, characterized in that, The module for calculating tubular friction and hydrostatic pressure is specifically used for: When the liquid type is clean water, the tubing friction of clean water is calculated according to the following formula based on the water discharge rate, tubing inner diameter, and the length of the clean water section within the tubing: in, Let Q be the frictional resistance of the tubing for clean water, D be the inner diameter of the tubing, and L be the length of the liquid section of the clean water within the tubing.

10. The apparatus as claimed in claim 8, characterized in that, The module for calculating tubular friction and hydrostatic pressure is specifically used for: When the liquid type is guar gum solution, the drag reduction ratio of the guar gum solution is calculated according to the following formula based on the guar gum solution discharge rate, column inner diameter, liquid section length of the guar gum solution in the column, and proppant concentration in the guar gum solution: in, The drag reduction ratio of the guar gum solution. This refers to the discharge volume of the guar gum solution. D The inner diameter of the tubular column, The sand concentration of the guar gum solution. G This refers to the concentration of the thickener.

11. The apparatus as claimed in claim 10, characterized in that, The module for calculating tubular friction and hydrostatic pressure is specifically used for: The column friction of guar gum solution is calculated using the following formula, based on the product of the drag reduction ratio of the guar gum solution and the column friction of the pure water solution: in, The friction of the tubing for the guar gum solution.

12. The apparatus as claimed in claim 8, characterized in that, The module for calculating tubular friction and hydrostatic pressure is specifically used for: Calculate the drag reduction ratio of sand-free guar gum solution using the following formula: in, The drag reduction ratio of the sand-free guar gum solution; The sand concentration is calculated to be 2.4 kg / m³ according to the following formula. 3 The drag reduction ratio of guar gum carrying sand fluid: in, This represents a sand concentration of 2.4 kg / m³. 3 The drag reduction ratio of the guar gum solution; Based on the drag reduction ratio of sand-free guar gum solution and a sand concentration of 2.4 kg / m³ 3 The drag reduction ratio of guar gum-carrying sand fluid is calculated using the following formula: in, C represents the drag reduction ratio of the slickwater, and C is the preset drag reduction ratio of the purified slickwater solution.

13. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 6.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.

15. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.

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