Non-blowing horizontal well liquid production profile monitoring method

Abstract

The invention relates to the technical field of oil and gas field development, in particular to a non-flowing horizontal well fluid production profile monitoring method which comprises the following steps: S1, cleaning sand and scraps in a shaft, and then closing the well; s2, a tubular column is assembled, the tubular column comprises a continuous oil pipe and an optical cable arranged in the continuous oil pipe in a penetrating mode, the optical cable comprises at least one multimode optical fiber and at least one single-mode optical fiber, the single-mode optical fibers are used for collecting noise data, and the multimode optical fibers are used for collecting temperature data; s3, 5-10 holes communicating inside and outside are formed in the outer side of the coiled tubing at intervals along the spiral line; and S4, a tubular column is put in. The purpose of monitoring the multi-section fracturing fluid production profile of the non-flowing horizontal well is achieved, the monitoring problems of poor measurement precision, complex tubular column structure and large operation risk are solved, the fluid production contribution rate and the fracturing effect of each cluster of reservoirs are accurately known through accurate monitoring of the fluid production profile, and an important basis is provided for reservoir recognition and optimization of a fracturing transformation scheme.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and is a method for monitoring the production profile of a non-flowing horizontal well. Background Art

[0002] my country is rich in low-permeability, shale oil and gas resources, which are expected to become important replacement resources. Pilot trials of low-permeability, shale oil and gas in domestic basins have confirmed that multi-stage, clustered volume fracturing in horizontal wells has become a key technology for improving EUR and achieving efficient development. However, low-permeability reservoirs generally have complex lithology and strong heterogeneity, resulting in significant differences in productivity after staged fracturing. Understanding the productivity effects of various stages and clusters under different fracturing techniques is crucial to verifying sweet spot reservoir classification and optimizing fracturing strategies.

[0003] The horizontal well production profile testing technology mainly includes crawler, continuous tubing connected flow meter (turbine flow meter, ultrasonic flow meter, electromagnetic flow meter) monitoring and fiber optic monitoring. The monitoring technology is mainly applicable to the conditions of self-flowing oil wells. For non-self-flowing horizontal wells with low formation pressure coefficient and long production time, the production profile monitoring is difficult.

[0004] Currently, there are several technologies for testing the production profile of non-flowing horizontal wells: Patent publication number CN105937393A (application number CN201610478540.X), published on September 14, 2016 (application date June 27, 2016), entitled "A Drag-Type Production Profile Testing String for Horizontal Wells and Its Testing Method." This document discloses a horizontal section of tubing equipped, from the toe to the heel, with a guide wire plug, eye tube, production profile tester, packer, and connecting pipe. A vertical section of tubing is equipped with a wellbore pump. The production profile tester is connected to a cable, which runs through a tee guide pipe at the bottom of the wellbore pump and connects to the wellhead equipment. During testing, the cable is dragged through the tubing to drive the production profile tester, measuring the production and water content of different layer combinations. However, this testing method suffers from a complex string structure, easily jamming the sand-producing packer, and high operational risks.

[0005] A Chinese patent document with publication number CN103075143A (application number CN201310052097.6), published on May 1, 2013 (application date February 18, 2013), and titled "A Method for Testing the Production Profile of a Mechanically Pumped Horizontal Well," discloses the following: a long-plunger hollow oil pump is connected to the bottom of a tubing and lowered into the horizontal well to the designed pumping depth, with the long-plunger hollow oil pump seat sealed within the casing. Coiled tubing and a logging cable are then simultaneously lowered through the tubing to the lower portion of a section to be tested for the production profile of the horizontal well. The coiled tubing is then pressurized on the surface to separate a release sub from the tubing, and the tubing is pulled out. A reciprocating surface lifting device is connected to the upper end of the tubing to perform a reciprocating pumping operation, and a production profile tester is activated. The testing cable is then slowly lifted to raise the production profile tester for testing while production is in progress. However, liquid production profile monitoring generally requires testing different production systems, and multiple rounds of lifting and lowering monitoring to eliminate measurement errors. At the same time, this method can only perform one test when the cable is lifted, and the instrument cannot be lowered for testing, which affects the measurement accuracy.

[0006] The Chinese patent document, Publication No. CN101403292A (Application No. CN200810137501.9), published on April 8, 2009 (Application Date: November 11, 2008), and titled "Process Method for Liquid Profile Measurement Using Gas Lift in Horizontal Wells," discloses a method for lifting a horizontal well using a gas lift production string. A crawler connected to a liquid profile tester is transported through the gas lift production string to the lower end of the test section. Nitrogen is then used to lift the liquid from the surface. After stabilization, the cable is pulled up to perform a liquid profile measurement. However, for wells with extremely long horizontal sections and poor wellbore trajectories, long-distance crawling is difficult, and monitoring of the entire horizontal section is not possible. Summary of the Invention

[0007] The present invention provides a method for monitoring the production profile of a non-flowing horizontal well, which overcomes the shortcomings of the above-mentioned existing technologies and can effectively solve the problems of poor measurement accuracy, complex pipe structure and high operation risk in the existing non-flowing horizontal well production profile monitoring.

[0008] The technical solution of the present invention is achieved by the following measures: A method for monitoring the fluid production profile of a non-flowing horizontal well comprises the following steps: S1, clean the sand and debris in the wellbore and then shut in the well; S2, assembling a tubing string, wherein the tubing string includes a coiled tubing and an optical cable running through the coiled tubing, wherein the optical cable includes at least one multimode optical fiber and at least one single-mode optical fiber, wherein the single-mode optical fiber is used to collect noise data, and the multimode optical fiber is used to collect temperature data; S3, 5 to 10 holes are opened on the outside of the coiled tubing along the spiral line at intervals, connecting the inside and the outside; S4, lower into the pipe string; S5, after the pipe string reaches the bottom of the man-made well, the light loss is monitored on the ground. If the light loss is abnormal, an inspection is initiated. If the light loss is normal, the process proceeds to step S6; S6, gas lift production; S7, select 2 to 3 continuous gas lift systems with different displacement rates for production. After the production stabilizes, the ground fiber optic acquisition equipment obtains fiber optic DTS / DAS data through multimode fiber and single-mode fiber; S8, after obtaining qualified data, the string is removed; S9, interpret and analyze the optical fiber DAS / DTS data to obtain the output of a single cluster.

[0009] The following are further optimizations and / or improvements to the above technical solutions: In the above step S3, the distance between the uppermost and lowermost holes is no more than 2 meters, and the diameter of the holes is 5 to 8 mm.

[0010] The above step S4 is: lowering the pipe string into the horizontal section, stopping the lowering 100 to 150 meters in front of the bottom of the artificial well, monitoring the optical loss of the multimode optical fiber and the single-mode optical fiber, and continuing to lower the pipe string if the optical loss is normal; if the optical loss is abnormal, an inspection is initiated.

[0011] The above step S6 includes the following steps: S61, connecting at least one multimode optical fiber and at least one single-mode optical fiber running through the coiled tubing to a ground optical fiber acquisition device; S62, monitoring the background temperature of the formation in the shut-in state; S63, when the background temperature stabilizes, the nitrogen generator truck is fixedly connected to the upper end of the coiled tubing; S64, nitrogen is pumped into the coiled tubing, and the nitrogen overflows from the holes to achieve gas lift production.

[0012] The above step S8 is: after obtaining qualified data, the tubing string is lifted, the coiled tubing corresponding to the hole is lifted out of the wellhead, the hole is welded and sealed, and then the tubing string is lifted out of the wellhead.

[0013] The present invention achieves the purpose of monitoring the fluid production profile of multi-stage fracturing in non-flowing horizontal wells, and solves the monitoring problems of poor measurement accuracy, complex tubing structure, and high operation risks. Through precise monitoring of the fluid production profile, the contribution rate of fluid production of each cluster reservoir and the fracturing effect are accurately understood, providing an important basis for reservoir understanding and optimization of fracturing transformation plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attachment Figure 1 This is a schematic diagram of the main cross-sectional structure of embodiment 1 of the present invention.

[0015] The codes in the accompanying drawings are: 1 for coiled tubing, 2 for casing, 3 for optical cable, and 4 for eyelet. DETAILED DESCRIPTION

[0016] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0017] In the present invention, for the convenience of description, the relative position relationship of each component is described based on the Figure 1 For example, the positional relationships of front, back, up, down, left, and right are determined according to the layout directions of the drawings in the specification.

[0018] The present invention will be further described below in conjunction with the embodiments and accompanying drawings: Example 1: As shown in the attached Figure 1 As shown, the method for monitoring the fluid production profile of a non-flowing horizontal well includes the following steps: S1, clean the sand and debris in the wellbore and then shut in the well; S2, assembling a tubing string, wherein the tubing string includes a coiled tubing 1 and an optical cable 3 passing through the coiled tubing 1, wherein the optical cable 3 includes at least one multimode optical fiber and at least one single-mode optical fiber, wherein the single-mode optical fiber is used to collect noise data, and the multimode optical fiber is used to collect temperature data; S3, 5 to 10 holes 4 are opened on the outside of the coiled tubing 1 along the spiral line at intervals, so as to communicate with the outside. S4, lower into the pipe string; S5, after the pipe string reaches the bottom of the man-made well, the light loss is monitored on the ground. If the light loss is abnormal, an inspection is initiated. If the light loss is normal, the process proceeds to step S6; S6, gas lift production; S7, select 2 to 3 continuous gas lift systems with different displacement rates for production. After the production stabilizes, the ground fiber optic acquisition equipment obtains fiber optic DTS / DAS data through multimode fiber and single-mode fiber; S8, after obtaining qualified data, the string is removed; S9, interpret and analyze the optical fiber DAS / DTS data to obtain the output of a single cluster.

[0019] The present invention achieves the purpose of monitoring the fluid production profile of multi-stage fracturing in non-flowing horizontal wells, and solves the monitoring problems of poor measurement accuracy, complex tubing structure, and high operation risks. Through precise monitoring of the fluid production profile, the contribution rate of fluid production of each cluster reservoir and the fracturing effect are accurately understood, providing an important basis for reservoir understanding and optimization of fracturing transformation plans.

[0020] The above-mentioned method for monitoring the fluid production profile of non-flowing horizontal wells can be further optimized and / or improved according to actual needs: Example 2: As an optimization of the above example, as shown in the attached Figure 1As shown, in step S3, the distance between the top and bottom holes 4 is no more than 2 meters, and the diameter of the hole 4 is 5 to 8 mm. This facilitates subsequent gas lift production, and gas lift production can be performed after nitrogen is injected into the coiled tubing 1.

[0021] Example 3: As an optimization of the above example, step S4 is as follows: lower the pipe string into the horizontal section, stop running 100 to 150 meters before the bottom of the man-made well, and monitor the optical loss of the multimode and single-mode optical fibers. If the optical loss is normal, continue running; if the optical loss is abnormal, initiate an inspection. This allows for timely detection of optical fiber anomalies, preventing maintenance difficulties caused by optical fiber failures after being lowered to the bottom of the man-made well.

[0022] Example 4: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, step S6 includes the following steps: S61, connecting at least one multimode optical fiber and at least one single-mode optical fiber running through the coiled tubing 1 to a ground optical fiber acquisition device; S62, monitoring the background temperature of the formation in the shut-in state; S63, when the background temperature stabilizes, the nitrogen generator truck is fixedly connected to the upper end of the coiled tubing 1; S64, nitrogen is pumped into the coiled tubing 1, and the nitrogen overflows from the hole 4 to realize gas lift production.

[0023] This allows the production of pumped oil wells to be converted to gas lift production, thereby enabling the monitoring of oil wells during normal production.

[0024] Example 5: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, step S8 is as follows: after obtaining qualified data, the tubing string is lifted, the coiled tubing 1 corresponding to the eyelet 4 is lifted out of the wellhead, the eyelet 4 is welded and sealed, and then the tubing string is lifted out of the wellhead. This allows the existing coiled tubing 1 to be used for monitoring the production profile of the horizontal well. Welding and sealing the eyelet 4 allows the coiled tubing 1 to be reused, reducing monitoring costs.

[0025] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

[0026] The process of the best embodiment of the present invention: The first step was to drill multi-stage fractured horizontal well M42 at a vertical depth of 2,500 meters. The distance from inclination point A to the bottom of the well was 1,200 meters. The well was initially pumped. Before testing, the pump was removed, and the wellbore was flushed using coiled tubing 1. The well was then shut in. The second step involves assembling a 6,200-meter-long, 2-inch coiled tubing (1). Four optical fibers are threaded through the coiled tubing, two of which are multimode and two are single-mode. One single-mode fiber and one multimode fiber are used for temperature and noise measurement, while the other two serve as backup. Step 3: Select a 2-meter-long coiled tubing 1 to be put into the well between the coiled tubing drum 1 and the coiled tubing injection head 1, and open 8 holes 4 spaced along the spiral line. The holes 4 have a diameter of 8 mm. Step 4: Run the string into the horizontal section and stop 100 meters before the bottom of the man-made well. Monitor the optical loss of the multimode fiber and single-mode fiber. If the optical loss is normal, continue running the string. Step 5: After the tubing string reaches the bottom of the man-made well, the light loss is monitored on the ground. The monitoring results show that the light loss is normal. Step 6: Connect a multimode optical fiber and a single-mode optical fiber running through the coiled tubing 1 to a surface optical fiber data acquisition device; monitor the background temperature of the formation in the shut-in state; when the background temperature stabilizes, securely connect a nitrogen generator truck to the upper end of the coiled tubing 1; pump nitrogen into the coiled tubing 1, and allow the nitrogen to escape from the perforations 4 to achieve gas lift production. In the seventh step, two continuous gas lift systems with different displacement rates were selected. After stabilization, the production rates under these two systems reached 20 cubic meters per day and 30 cubic meters per day, respectively. Ground-based fiber optic acquisition equipment acquired fiber DTS / DAS data through multimode and single-mode optical fibers. Step 8: After obtaining qualified data, the tubing is lifted, the coiled tubing 1 corresponding to the hole 4 is lifted out of the wellhead, the hole 4 is welded and sealed and polished smooth, and then the tubing is lifted out of the wellhead; The ninth step is to interpret and analyze the optical fiber DAS / DTS data to obtain the output of a single cluster.

[0027] The present invention has been applied and verified in multiple blocks of the Northwest Oilfield, achieving accurate understanding of the contribution rate of each cluster to liquid production, which is of great significance for reservoir understanding and optimization of fracturing schemes.

Claims

1. A method for monitoring the fluid production profile of a non-flowing horizontal well, characterized in that The steps are as follows: S1, clean the sand and debris in the wellbore and then shut in the well; S2, assembling a tubing string, wherein the tubing string includes a coiled tubing and an optical cable running through the coiled tubing, wherein the optical cable includes at least one multimode optical fiber and at least one single-mode optical fiber, wherein the single-mode optical fiber is used to collect noise data, and the multimode optical fiber is used to collect temperature data; S3, 5 to 10 holes are opened on the outside of the coiled tubing along the spiral line at intervals, connecting the inside and the outside; S4, lower into the pipe string; S5, after the pipe string reaches the bottom of the man-made well, the light loss is monitored on the ground. If the light loss is abnormal, an inspection is initiated. If the light loss is normal, the process proceeds to step S6; S6, gas lift production; S7, select 2 to 3 continuous gas lift systems with different displacement rates for production. After the production stabilizes, the ground fiber optic acquisition equipment obtains fiber optic DTS / DAS data through multimode fiber and single-mode fiber; S8, after obtaining qualified data, the string is removed; S9, interpret and analyze the optical fiber DAS / DTS data to obtain the output of a single cluster.

2. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 1, characterized in that: In step S3, the distance between the uppermost and lowermost holes is no more than 2 meters, and the diameter of the holes is 5 to 8 mm.

3. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 1 or 2, characterized in that: Step S4 is: lowering the pipe string into the horizontal section, stopping the lowering 100 to 150 meters in front of the bottom of the artificial well, monitoring the optical loss of the multimode optical fiber and the single-mode optical fiber, and continuing to lower the pipe string if the optical loss is normal; if the optical loss is abnormal, an inspection is initiated.

4. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 1 or 2, characterized in that: Step S6 includes the following steps: S61, connecting at least one multimode optical fiber and at least one single-mode optical fiber running through the coiled tubing to a ground optical fiber acquisition device; S62, monitoring the background temperature of the formation in the shut-in state; S63, when the background temperature stabilizes, the nitrogen generator truck is fixedly connected to the upper end of the coiled tubing; S64, nitrogen is pumped into the coiled tubing, and the nitrogen overflows from the holes to achieve gas lift production.

5. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 3, characterized in that: Step S6 includes the following steps: S61, connecting at least one multimode optical fiber and at least one single-mode optical fiber running through the coiled tubing to a ground optical fiber acquisition device; S62, monitoring the background temperature of the formation in the shut-in state; S63, when the background temperature stabilizes, the nitrogen generator truck is fixedly connected to the upper end of the coiled tubing; S64, nitrogen is pumped into the coiled tubing, and the nitrogen overflows from the holes to achieve gas lift production.

6. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 1, 2 or 5, wherein: Step S8 is: after obtaining qualified data, the tubing is lifted, the coiled tubing corresponding to the hole is lifted out of the wellhead, the hole is welded and sealed, and then the tubing is lifted out of the wellhead.

7. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 3, characterized in that: Step S8 is: after obtaining qualified data, the tubing is lifted, the coiled tubing corresponding to the hole is lifted out of the wellhead, the hole is welded and sealed, and then the tubing is lifted out of the wellhead.

8. The method for monitoring the fluid production profile of a non-flowing horizontal well according to claim 4, characterized in that: Step S8 is: after obtaining qualified data, the tubing is lifted, the coiled tubing corresponding to the hole is lifted out of the wellhead, the hole is welded and sealed, and then the tubing is lifted out of the wellhead.

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