A straight well horizontal slit fracturing field construction control method

Abstract

The present application relates to the technical field of oil production engineering, and particularly relates to a straight well horizontal fracture field construction control method. The method comprises the following steps: determining a fracturing target well, obtaining basic data of the fracturing target well, calculating preflush liquid dosage, temporary plugging times and temporary plugging agent dosage of single temporary plugging according to the obtained basic data; opening the stratum and stopping pumping, and recording the pump stopping pressure A; performing fracturing construction on the fracturing target well, injecting temporary plugging agent, observing the pressure rise of the fracturing target well, and judging whether single temporary plugging is effective according to the pressure rise; in the case that single temporary plugging is effective, continuing to add fracturing fluid to the fracturing target well for construction, stopping pumping and recording the pump stopping pressure B; observing whether the pump stopping pressure A and the pump stopping pressure B are equal, if not, repeating the operation until the two are equal, and stopping. The method provided by the present application has strong controllability, and is convenient, simple, safe and effective to operate.

Description

Technical Field

[0001] This invention relates to the technical field of oil production engineering, and in particular to a method for on-site construction control of horizontal fracture fracturing in vertical wells. Background Technology

[0002] Currently, the on-site construction control of horizontal fracture fracturing and temporary plugging-and-redirection fracturing in wells mainly relies on the experience of technical personnel, lacking a systematic on-site construction control method. Therefore, in actual construction, problems such as excessive or insufficient pressure rise after temporary plugging are prone to occur, making it impossible to ensure the effectiveness of temporary plugging within the horizontal fracture while guaranteeing construction safety. Therefore, to address these shortcomings, a method for on-site construction control of horizontal fracture fracturing in vertical wells is proposed. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] This invention provides a method for on-site construction control of horizontal fracture fracturing in vertical wells, which overcomes the problems in the prior art where the lack of a systematic on-site construction control method easily leads to problems such as excessive pressure rise after temporary plugging or insufficient pressure rise after temporary plugging, resulting in the inability to ensure the effectiveness of temporary plugging within the horizontal fracture.

[0005] (II) Technical Solution

[0006] To address the above problems, this invention provides a method for on-site construction control of horizontal fracture fracturing in vertical wells, comprising:

[0007] Step S1: Determine the target well for fracturing and obtain the basic data of the target well;

[0008] Step S2: Based on the basic data of the target fracturing well obtained in Step S1, calculate the amount of pre-flush fluid, the number of temporary plugging times, and the amount of plugging agent used per temporary plugging.

[0009] Step S3: Perform pre-fracturing with fluid to create fractures in the target well of step S1, break up the formation, and record the pump shutdown pressure A;

[0010] Step S4: After completing the measurement of the pump stop pressure in step S3, carry out the pre-flush liquid sand addition construction according to the calculation results of S2;

[0011] Step S5: After the time for adding the temporary plugging agent calculated in Step S2 is reached, the temporary plugging agent is added. Based on the basic data of the field environment, the time required for the temporary plugging agent to reach the front end of the horizontal fracture of the target well and the time of addition of the temporary plugging agent are calculated. The speed of adding the temporary plugging agent is controlled according to the result of the amount of temporary plugging agent used in Step S2.

[0012] Step S6: Observe the pressure increase of the target well during the calculation time of step S5, and determine whether the single temporary plugging is effective based on the pressure increase;

[0013] Step S7: If the single temporary plugging in step S6 is confirmed to be effective, continue to add fracturing fluid to the target well, stop the pump and record the pump stop pressure B;

[0014] Step S8: Observe whether the pump stop pressure A in step S3 and the pump stop pressure B in step S7 are equal. If they are not equal, repeat the process from step S4 to step S7 until they are equal, and then stop the operation.

[0015] Preferably, in step S1, the target fracturing well is a vertical well with a horizontal fracture, and the basic data of the target fracturing well includes the reservoir stimulation radius, the bottom depth of the target layer, the internal volume of the pipeline, the fluid efficiency, the temporary plugging length at the front end of the horizontal fracture, and the fracture height of the horizontal fracture.

[0016] Preferably, in step S4, the sand discharge rate is 2m³. 3 / min-5m 3 / min, wherein the sand ratio is 5%-10%, and the sand ratio is the ratio of the volume of sand to the volume of fracturing fluid.

[0017] Preferably, the type of sand includes quartz sand, resin sand, ceramic gravel, or a coated support agent.

[0018] Preferably, in step S5, the timing of adding the temporary plugging agent is calculated based on the construction discharge rate and the on-site application speed, and the timing of adding the temporary plugging agent is 1 minute remaining before the end of sand addition.

[0019] Preferably, the basic data of the site environment includes the inner diameter of the oil pipe, the volume of the ground pipeline, and the construction discharge rate.

[0020] Preferably, in step S5, the result of the temporary plugging agent dosage is limited to 100 kg. If the temporary plugging agent dosage is less than 100 kg, the temporary plugging agent is added within 1 minute after the preset time for adding sand is reached. If the calculated dosage of the temporary plugging agent is greater than 100 kg, 100 kg of temporary plugging agent is added together with sand within 1 minute. After 1 minute, the remaining temporary plugging agent is added at the same temporary plugging agent addition rate.

[0021] Preferably, in step S6, the pressure increase is limited to 3 MPa. If the pressure increase exceeds 3 MPa, it proves that the temporary blockage is successful.

[0022] (III) Beneficial Effects

[0023] The present invention provides a method for on-site construction control of horizontal fracture fracturing in vertical wells, which includes five steps: pretreatment before sand addition, calculation of temporary plugging agent dosage, method of adding temporary plugging agent, diagnosis of whether temporary plugging of a single horizontal fracture is successful, and diagnosis of whether temporary plugging within the horizontal fracture is successful. This construction method is highly controllable, easy and simple to operate, safe and effective. It can not only ensure construction safety, but also ensure the success of temporary plugging of horizontal fractures. Attached Figure Description

[0024] Figure 1 This is a flowchart of the on-site construction control method for horizontal fracture fracturing in a vertical well, according to an embodiment of the present invention.

[0025] Figure 2 This is a construction curve diagram of fracturing a well in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Figure 1 This is a flowchart of the on-site construction control method for horizontal fracture fracturing in vertical wells according to an embodiment of the present invention, such as... Figure 1 As shown, the present invention provides a method for on-site construction control of horizontal fracture fracturing in vertical wells, comprising:

[0028] Step S1: Determine the target well for fracturing and obtain the basic data of the target well;

[0029] Step S2: Based on the basic data of the target fracturing well obtained in Step S1, calculate the amount of pre-flush fluid, the number of temporary plugging times, and the amount of plugging agent used per temporary plugging.

[0030] Step S3: Perform pre-fracturing with fluid to create fractures in the target well of step S1, break up the formation, and record the pump shutdown pressure A;

[0031] Step S4: After completing the measurement of the pump stop pressure in step S3, carry out the pre-flush liquid sand addition construction according to the calculation results of S2;

[0032] Step S5: After the time for adding the temporary plugging agent calculated in Step S2 is reached, the temporary plugging agent is added. Based on the basic data of the field environment, the time required for the temporary plugging agent to reach the front end of the horizontal fracture of the target well and the time of addition of the temporary plugging agent are calculated. The speed of adding the temporary plugging agent is controlled according to the result of the amount of temporary plugging agent used in Step S2.

[0033] Step S6: Observe the pressure increase of the target well during the calculation time of step S5, and determine whether the single temporary plugging is effective based on the pressure increase;

[0034] Step S7: If the single temporary plugging in step S6 is confirmed to be effective, continue to add fracturing fluid to the target well, stop the pump and record the pump stop pressure B;

[0035] Step S8: Observe whether the pump stop pressure A in step S3 and the pump stop pressure B in step S7 are equal. If they are not equal, repeat the process from step S4 to step S7 until they are equal, and then stop the operation.

[0036] In practical applications, in step S1, the target well for fracturing is a vertical well with a horizontal fracture. The basic data of the target well for fracturing includes the reservoir stimulation radius, the bottom depth of the target layer, the internal volume of the pipeline, the fluid efficiency, the temporary plugging length at the front end of the horizontal fracture, and the fracture height of the horizontal fracture.

[0037] In this method, in step S2, based on the basic data of the target fracturing well obtained in step S1, the amount of pre-flush fluid, the number of temporary plugging times, and the amount of plugging agent used per temporary plugging are calculated.

[0038] In practical applications, the sand discharge rate in step S4 is 2m. 3 / min-5m 3 / min, the type of sand added includes quartz sand, resin sand, ceramic gravel or film proppant, and the sand ratio is 5%-10%, which is the ratio of the volume of sand to the volume of fracturing fluid.

[0039] In this method, in step S5, the basic data of the field environment include the inner diameter of the tubing, the volume of the surface pipeline, and the construction discharge rate. Based on the inner diameter of the tubing, the volume of the surface pipeline, and the construction discharge rate, the time required for the temporary plugging agent to reach the front end of the fracturing target well can be calculated. Based on the construction discharge rate and the field delivery speed, the time for adding the temporary plugging agent is calculated. The temporary plugging agent is delivered starting 1 minute before the sand addition ends.

[0040] In practical applications, in step S5, the limit value for the amount of temporary plugging agent is 100 kg. If the amount of temporary plugging agent is less than 100 kg, the temporary plugging agent will be added within 1 minute after the preset time for adding sand is reached. If the calculated amount of temporary plugging agent is greater than 100 kg, 100 kg of temporary plugging agent will be added together with sand within 1 minute. After 1 minute, the remaining temporary plugging agent will be added at the same rate.

[0041] In this method, in step S6, the pressure increase is limited to 3 MPa. If the pressure increase exceeds 3 MPa, it proves that the temporary plugging is successful. If the pressure increase is less than 3 MPa, the amount of temporary plugging agent can be increased until the pressure increase reaches 3 MPa.

[0042] The following describes in detail the implementation process of this method for on-site construction control of horizontal fracture fracturing in vertical wells:

[0043] In this embodiment, the target well for fracturing is determined, and the basic data of the target well for fracturing is obtained.

[0044] Calculate the amount of pre-fluid used, the number of times temporary plugging is performed, the timing of adding the temporary plugging agent, and the amount of temporary plugging agent used per temporary plugging.

[0045] Press open the formation to test and stop the pump, and record the pump stop pressure A.

[0046] In practical applications, after the formation was broken up, the pump shutdown pressure was tested at 13.28 MPa, and the bottom depth of the target formation was 1005.4 m. Figure 2 As shown, the calculated pump stop pressure gradient A = 0.0232 MPa / m.

[0047] In practical applications, by obtaining the basic data of the target well in the first step, we can know that the reservoir stimulation radius is 60m, the horizontal fracture height is 0.001m, and the horizontal fracture front length is 0.2m. Based on these data, we can calculate that there are 3 temporary plugging times and the amount of temporary plugging agent used each time is 300kg.

[0048] In this embodiment, after the pre-flush fluid is used to create fractures, sand is added. The time required for the temporary plugging agent to reach the front end of the horizontal fracture of the target well is calculated. Based on the tubing inner diameter, surface pipeline volume, and construction flow rate, the time required for the temporary plugging agent to reach the front end of the target well can be calculated. The timing of adding the temporary plugging agent is calculated based on the construction flow rate and the on-site delivery speed. In practical applications, the temporary plugging agent is usually added starting 1 minute before the sand addition is completed. After the time for adding the temporary plugging agent is reached, the addition speed is controlled based on the amount of temporary plugging agent used.

[0049] In practical applications, the first step is to create a suture using a pre-fluid injection, followed by a 3m... 3 The discharge rate is / min, the type of sand added is quartz sand, and the sand ratio is 10%, that is, at a discharge rate of 20m³ / min. 3 Add 2m³ of quartz sand to the fracturing fluid volume 3 Because the amount of temporary plugging agent used in a single application exceeds 100 kg, therefore, from Figure 2 It can be seen that time E is the preset time, and there is 1 minute remaining before the sand addition ends. When the sand addition time reaches time E, 100 kg of temporary plugging agent is added from time E until the end of this sand addition. After the sand addition ends, 200 kg of temporary plugging agent is added at the same rate.

[0050] In this embodiment, the pressure increase of the target well is observed, and the effectiveness of a single temporary plugging is determined based on the pressure increase.

[0051] In practical applications, after temporary closure, the pressure rise was measured. The pressure increased from 26.4 MPa to 29.6 MPa, an increase of 3.2 MPa, proving that the temporary closure was successful.

[0052] In this embodiment, if the single temporary plugging is determined to be effective, fracturing fluid is added to the target well, the pump is stopped and the stop pressure B is recorded. The stop pressure A and stop pressure B are observed to see if they are equal. If they are not equal, the process of implementing the single temporary plugging is repeated until they are equal, and then the operation is stopped.

[0053] In practical applications, after a successful temporary blockage, the measured pump stop pressure B is 12.17 MPa. Since A ≠ B, the operation is repeated as follows: Figure 2 As shown, F and G are the times when the temporary plugging agent is added for the second and third time, respectively. The pump stop pressures C and D were measured for the second and third times, respectively. The pump stop pressure C was 12.48 MPa and the pump stop pressure D was 12.50 MPa. Since the pump stop pressure C ≈ D, it can be determined that the temporary plugging of the horizontal joint was successful.

[0054] The present invention provides a method for on-site construction control of horizontal fracture fracturing in vertical wells, which includes five steps: pretreatment before sand addition, calculation of temporary plugging agent dosage, method of adding temporary plugging agent, diagnosis of whether temporary plugging of a single horizontal fracture is successful, and diagnosis of whether temporary plugging within the horizontal fracture is successful. This construction method is highly controllable, easy and simple to operate, safe and effective. It can not only ensure construction safety, but also ensure the success of temporary plugging of horizontal fractures.

[0055] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims.

Claims

1. A method for on-site construction control of horizontal fracture fracturing in vertical wells, characterized in that, include: Step S1: Determine the target well for fracturing and obtain the basic data of the target well; The target well for fracturing is a vertical well with a horizontal fracture. The basic data of the target well for fracturing includes the reservoir stimulation radius, the bottom depth of the target layer, the internal volume of the pipeline, the fluid efficiency, the temporary plugging length at the front end of the horizontal fracture, and the fracture height of the horizontal fracture. Step S2: Based on the basic data of the target fracturing well obtained in Step S1, calculate the amount of pre-flush fluid, the number of temporary plugging times, and the amount of plugging agent used per temporary plugging. Step S3: Perform pre-fracturing with fluid to create fractures in the target well of step S1, break up the formation, and record the pump shutdown pressure A; Step S4: After completing the measurement of the pump stop pressure in step S3, carry out the pre-flush liquid sand addition construction according to the calculation results of S2; Step S5: After the time for adding the temporary plugging agent calculated in Step S2 is reached, the temporary plugging agent is added. Based on the basic data of the field environment, the time required for the temporary plugging agent to reach the front end of the horizontal fracture of the target well and the time of addition of the temporary plugging agent are calculated. The speed of adding the temporary plugging agent is controlled according to the result of the amount of temporary plugging agent used in Step S2. Step S6: Observe the pressure increase of the target well during the calculation time of step S5, and determine whether the single temporary plugging is effective based on the pressure increase; Step S7: If the single temporary plugging in step S6 is confirmed to be effective, continue to add fracturing fluid to the target well, stop the pump and record the pump stop pressure B; Step S8; Observe whether the pump stop pressure A in step S3 and the pump stop pressure B in step S7 are equal. If they are not equal, repeat the process from step S4 to step S7 until they are equal, and then stop the operation.

2. The method for on-site construction control of horizontal fracture fracturing in vertical wells according to claim 1, characterized in that, In step S4, the sand discharge rate is 2m³. 3 / min-5m 3 / min, sand ratio of 5%-10%, where sand ratio is the ratio of sand volume to fracturing fluid volume.

3. The method for on-site construction control of horizontal fracture fracturing in vertical wells according to claim 2, characterized in that, The types of sand include quartz sand, resin sand, ceramic gravel, or coated proppant.

4. The method for on-site construction control of horizontal fracture fracturing in vertical wells according to claim 1, characterized in that, In step S5, the timing of adding the temporary plugging agent is calculated based on the construction discharge rate and the on-site application speed. The timing of adding the temporary plugging agent is 1 minute remaining before the sand addition is completed.

5. The method for on-site construction control of horizontal fracture fracturing in vertical wells according to claim 1, characterized in that, In step S5, the basic data of the site environment includes the inner diameter of the oil pipe, the volume of the ground pipeline, and the construction discharge rate.

6. The method for on-site construction control of horizontal fracture fracturing in vertical wells according to claim 1, characterized in that, In step S5, the limit value of the amount of temporary plugging agent is 100 kg. If the amount of temporary plugging agent is less than 100 kg, the temporary plugging agent will be added within 1 minute after the preset time for adding sand is reached. If the calculated amount of temporary plugging agent is greater than 100 kg, 100 kg of temporary plugging agent will be added together with sand within 1 minute. After 1 minute, the remaining temporary plugging agent will be added at the same temporary plugging agent addition rate.

7. The method for on-site construction control of horizontal fracture fracturing in vertical wells according to claim 1, characterized in that, In step S6, the pressure increase is limited to 3 MPa. If the pressure increase exceeds 3 MPa, it proves that the temporary blockage is successful.

Images