Horizontal well fluid production profile testing method

Abstract

The invention relates to a horizontal well fluid production profile testing method, and belongs to the technical field of oil and gas field testing. The method comprises the following specific steps: step 1, preparation work before testing; secondly, segmented setting is carried out; step 3, data acquisition; fourthly, the logging instrument is recycled; and 5, explaining a liquid production profile. The logging instrument with the soluble metal is combined with a perforating gun and a soluble bridge plug, so that the technical problem of evaluating the fracturing effect of the horizontal well with the long horizontal section is solved, the testing time of the liquid production profile of each section of the long horizontal section is shortened, and the testing success rate and the testing efficiency are improved.

Description

Technical Field

[0001] The invention relates to a method for testing a production fluid profile of a horizontal well, belonging to the technical field of oil and gas field testing. Background Art

[0002] The horizontal well production fluid profile testing technology can understand the production and flowback rules of each fracturing layer, understand the downhole production dynamics, provide a basis for production optimization, and play a role in increasing oil and gas well production and reducing development costs.

[0003] The horizontal well production profile testing technology mainly uses continuous tubing or crawlers to transport test instruments with multiple sensors to test parameters such as pressure, temperature, and flow in each layer. However, there is a problem of high testing costs for both continuous tubing and crawlers for instrument transportation. When the horizontal section exceeds a certain length, the continuous tubing's transportation capacity deteriorates, and the crawler will slip and have insufficient traction. In addition, when the well conditions are complex and there are residual debris in the well, the crawler is in danger of getting stuck underground. The probability of test failure is extremely high, and the construction is complex and costly. At present, there is a lack of low-cost and efficient production profile testing methods for multi-stage fracturing horizontal wells.

[0004] Correctly understanding the geometry and extension of fracturing cracks plays an important guiding role in evaluating the fracturing effect, improving the accuracy of fracturing design, optimizing development plans, and thus improving the productivity of single wells. Common fracture monitoring methods include well test analysis, well temperature logging, radioactive tracer logging, and microseismic method. Radioactive tracer logging requires the use of radioactive tracer ceramsite, which has certain radioactive pollution to people and the environment and is inconvenient to use. Microseismic method requires the deployment of a large number of detectors on the ground or underground, and the construction process is complex, the cycle is long, and the price is expensive. In addition, the method itself has certain uncertainties and lacks the necessary comparative verification methods. The interpretation of data errors needs to be further understood. The well temperature before and after fracturing and the pressure recovery data after fracturing can be used for well test analysis to calculate the fracture parameters of each layer. Well test analysis and well temperature logging technology are mature and cheap, but conventional temperature and pressure testing processes are not suitable for multi-stage fracturing of horizontal wells. At present, there is no feasible and convenient well temperature logging and post-fracturing data testing method for multi-stage fracturing horizontal wells. It is impossible to master the pressure recovery data of each section, and it cannot meet the testing needs of fracturing fracture well test analysis. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention discloses a horizontal well production profile testing method, which meets the requirements of production profile and pressure recovery testing, and has the advantages of low construction cost, high test success rate, high test efficiency and high test instrument recovery efficiency.

[0006] The technical solution adopted by the present invention is a method for testing the production profile of a horizontal well, and the specific steps are as follows:

[0007] Step 1: Preparation before testing;

[0008] Step 2: Carry out segmented sealing;

[0009] Step 3: data collection;

[0010] Step 4, recovering the logging instrument;

[0011] Step five: interpret the fluid production profile.

[0012] Furthermore, the step one specifically includes programming the logging instrument before it is lowered, and setting the delayed start time of the instrument according to the fracturing plan; numbering each logging instrument, corresponding to the well number, soluble bridge plug and its fracturing layer section, and writing this information into the memory of the corresponding logging instrument.

[0013] Furthermore, the logging instrument is encapsulated with soluble metal by epoxy resin.

[0014] Furthermore, the density of the soluble metal is greater than the density of the well fluid.

[0015] Furthermore, the soluble metal is an aluminum-magnesium alloy or a magnesium-lithium alloy.

[0016] Furthermore, the step 2 specifically includes lowering a numbered logging instrument into the well according to the setting, the density of the logging instrument is slightly greater than that of the well fluid, and during construction, before fracturing each layer, the logging instrument relies on its own gravity to be lowered to the heel of the horizontal well, that is, the starting position of the horizontal section, and during fracturing, the logging instrument is pumped to the target horizontal section along with the movement of the fracturing fluid; then, the tail end of the cable is connected to the perforating gun and the soluble bridge plug in turn on the ground, and during cluster perforation, the soluble bridge plug is transported to the position where the bridge plug needs to be seated in the horizontal section as the pump truck pumps in the fracturing fluid. In this process, the previously lowered logging instrument is seated in the target layer together with the soluble bridge plug; the cable is pulled up, and the previous steps are repeated until all the soluble bridge plugs are seated and the logging instrument is placed.

[0017] Furthermore, the step three specifically includes collecting data according to the instrument delay start time and sampling period set in the fracturing plan after the logging instrument is lowered into the well, and recording the temperature, pressure and acceleration data of the corresponding fracturing layer section in the well.

[0018] Furthermore, the step 4 specifically includes that after the soluble bridge plug is dissolved, the soluble metal of the logging instrument placed in each layer section is also completely dissolved. At this time, the density of the logging instrument is less than the density of the well fluid and it floats in the well fluid, completing the recovery of the logging instrument.

[0019] Furthermore, the step five specifically includes playing back and reading out the test data in the memory through a computer, and identifying the serial number of each logging instrument to obtain the production profile data collected by the logging instrument and the pressure recovery data of each fracturing layer segment.

[0020] Furthermore, the production profile data includes temperature, pressure and production data of each layer section downhole; the temperature and pressure data of the production layer are directly obtained from the temperature and pressure data recorded by the logging instrument, and the temperature and pressure data of the layer section where each logging instrument is located are determined according to the number of each logging instrument; the flow data of each production layer is comprehensively judged through the instrument acceleration information and the time for each logging instrument to reach the vertical well section; then, the pressure recovery data of each production layer section obtained by the logging instrument is combined with the well test analysis method to calculate the fracture parameters and reservoir parameters.

[0021] The invention discloses a method for testing the production profile of a horizontal well. The method has the beneficial effect of combining the well logging instrument with soluble metal with a perforating gun and a soluble bridge plug, thereby solving the technical problem of evaluating the fracturing effect of a horizontal well with a long horizontal section, shortening the testing time of the production profile of each section of the long horizontal section, and improving the test success rate and test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 The figure shows the schematic diagram of the logging tool being lowered by its own weight in Example 1;

[0024] Figure 2 The figure shows a schematic diagram of the placement process of the logging tool in Example 1;

[0025] Figure 3 The figure shows the schematic diagram of the completion of the placement of the logging tool in Example 1;

[0026] Figure 4 Shown is a schematic diagram of the logging tool and soluble metal in Example 1.

[0027] Reference numerals in the figure: 1. perforating gun; 2. soluble bridge plug; 3. logging instrument; 4. cable; 5. fracturing layer; 6. soluble metal.

[0028] Specific implementation methods

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In order to further understand the content of the present invention, the present invention is further described below in conjunction with specific implementation methods.

[0031] Example 1: Figures 1 to 4 As shown, a method for testing the production profile of a horizontal well is provided. In this embodiment, three logging instruments 3 with soluble metals 6 are lowered, and the density of the logging instruments 3 with soluble metals 6 is slightly greater than that of the well fluid. Specifically, the method includes:

[0032] Step 1, preparatory work before testing; specifically, the well logging instrument 3 is programmed before being lowered, and the delayed start time of the instrument is set according to the fracturing plan; each well logging instrument 3 is numbered, and the corresponding well number, soluble bridge plug 2 and its fracturing layer section 5 are respectively written into the memory of each well logging instrument 3. The well logging instrument 3 is sampled and set according to the fracturing design time stage arrangement, so that its data collection cycle is consistent with the fracturing construction, and the instrument is in a dormant state from before the instrument is lowered into the well to before the corresponding fracturing layer section 5 of the well starts, saving the instrument power and storage space; in this embodiment, the soluble metal 6 is an aluminum-magnesium alloy, and it should be noted that the soluble metal satisfies that the density is greater than the density of the drilling fluid and dissolves in the downhole electrolyte environment.

[0033] Step 2: perform segmented sealing; specifically, the first logging instrument 3 is lowered into the well according to the setting. During construction, before fracturing each layer, the logging instrument 3 is lowered to the heel of the horizontal well (the starting position of the horizontal section) by its own gravity. During fracturing, the logging instrument 3 is pumped to the target horizontal section along with the movement of the fracturing fluid; then, the tail end of the cable 4 is connected to the perforating gun 1 and the soluble bridge plug 2 on the ground in sequence. During cluster perforation, the soluble bridge plug 2 is transported to the position where the bridge plug needs to be sealed in the horizontal section as the pump truck pumps in the fracturing fluid. In this process, the first logging instrument 3 that was lowered previously is sealed in the target layer section together with the soluble bridge plug 2; the cable 4 is pulled up and re-entered in the wellbore. The second logging instrument 3 is lowered into the well according to the setting. During construction, before fracturing each layer, the logging instrument 3 is lowered to the heel of the horizontal well (the starting position of the horizontal section) by its own gravity. During fracturing, the logging instrument 3 is pumped to the target horizontal section along with the movement of the fracturing fluid; then, the tail end of the cable 4 is connected to the perforating gun 1 and the soluble bridge plug 2 on the ground in sequence. During cluster perforation, the soluble bridge plug 2 is transported to the position where the bridge plug needs to be seated in the horizontal section as the pump truck pumps in the fracturing fluid. In this process, the previously lowered logging instrument 3 is seated in the target layer together with the soluble bridge plug 2; the above steps are repeated repeatedly until three soluble bridge plugs 2 are seated and the logging instrument 3 is placed.

[0034] Step three, data collection; specifically, after the logging instrument 3 is lowered into the well, data is collected according to the instrument delay start time and sampling period set in the fracturing plan, and the temperature, pressure and acceleration data of the corresponding fracturing layer section 5 in the well are recorded, and the data are stored in respective memories.

[0035] Step 4, recovering the logging instrument 3; specifically, after a certain period of time after all the layer segments have been fracturing, the soluble bridge plug 2 and the soluble metal 6 of the logging instrument 3 are dissolved and completely dissolved in the downhole electrolyte environment. At this time, the density of the logging instrument 3 is less than the density of the well fluid, and the horizontal well fracturing fluid return stage is entered. The downhole liquid reaches the wellhead under the action of the formation pressure, and returns to the ground through the oil nozzle with a diameter of about 2 mm at the wellhead to enter the ground production pipeline; when the fracturing fluid is returned, since the fracturing fluid and the formation production fluid have a certain viscosity, and the density of the logging instrument 3 is slightly less than the well fluid, the logging instrument 3 is carried by the fracturing fluid and returned to the ground with the liquid, completing the recovery of the logging instrument 3.

[0036] Step 5, interpreting the fluid production profile, specifically includes replaying and reading the test data in the memory through a computer, and identifying the serial number of each logging instrument 3 to obtain the fluid production profile data collected by the logging instrument 3 and the pressure recovery data of each fractured layer section 5 .

[0037] Furthermore, the production profile data includes temperature, pressure and production data of each layer section downhole; the temperature and pressure data of the production layer are directly obtained from the temperature and pressure data recorded by the logging instrument 3, and the temperature and pressure data of the layer section where each logging instrument 3 is located are determined according to the number of each logging instrument 3; the flow data of each production layer is comprehensively judged through the instrument acceleration information and the time for each logging instrument 3 to reach the vertical well section; then, the pressure recovery data of each production layer section obtained by the logging instrument 3 is combined with the well test analysis method to calculate the fracture parameters and reservoir parameters.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing a horizontal well production profile, characterized in that: The specific steps are as follows: Step 1: Preparation before testing; Step 2: Carry out segmented sealing; Step 3: Data collection; Step 4, recovering the logging instrument; Step five: interpret the fluid production profile.

2. A method for testing a horizontal well production profile according to claim 1, characterized in that: Step one specifically includes programming the logging instrument (3) before it is lowered, and setting the delayed start time of the instrument according to the fracturing plan; numbering each logging instrument (3), respectively corresponding to the well number, the soluble bridge plug (2) and the fracturing layer section (5), and writing this information into the memory of the corresponding logging instrument (3).

3. A method for testing a horizontal well production profile according to claim 2, characterized in that: The logging instrument (3) is encapsulated with a soluble metal (6) by epoxy resin.

4. A method for testing a horizontal well production profile according to claim 3, characterized in that: The density of the soluble metal (6) is greater than the density of the well fluid.

5. A method for testing a horizontal well production profile according to claim 4, characterized in that: The soluble metal (6) is an aluminum-magnesium alloy or a magnesium-lithium alloy.

6. A method for testing a horizontal well production profile according to claim 5, characterized in that: Step 2 specifically includes lowering a numbered logging instrument (3) into the well according to the setting. The density of the logging instrument (3) is slightly greater than that of the well fluid. During construction, before fracturing each layer, the logging instrument (3) is lowered to the heel of the horizontal well by its own gravity, that is, the starting position of the horizontal section. During fracturing, the logging instrument (3) is pumped to the target horizontal section along with the movement of the fracturing fluid; then, the tail end of the cable (4) is connected to the perforating gun (1) and the soluble bridge plug (2) on the ground in sequence. During cluster perforation, the soluble bridge plug (2) is transported to the position where the bridge plug needs to be seated in the horizontal section as the pump truck pumps in the fracturing fluid. During this process, the previously lowered logging instrument (3) is seated in the target layer section together with the soluble bridge plug (2); the cable (4) is lifted up, and the previous steps are repeated until all the soluble bridge plugs (2) are seated and the logging instrument (3) is placed.

7. A method for testing a horizontal well production profile according to claim 1, characterized in that: Step three specifically includes collecting data after the logging instrument (3) is lowered into the well according to the instrument delay start time and sampling period set in the fracturing plan, and recording the temperature, pressure and acceleration data of the corresponding fracturing layer section (5) downhole.

8. A method for testing a horizontal well production profile according to claim 1, characterized in that: Step 4 specifically includes that after the soluble bridge plug (2) is dissolved, the soluble metal (6) of the logging instrument (3) placed in each fracturing layer section (5) is also completely dissolved. At this time, the density of the logging instrument (3) is less than the density of the well fluid and it floats in the well fluid, completing the recovery of the logging instrument (3).

9. A method for testing a horizontal well production profile according to claim 1, characterized in that: Step five specifically includes playing back and reading the test data in the memory through a computer, and identifying the serial number of each logging instrument (3) to obtain the production profile data collected by the logging instrument (3) and the pressure recovery data of each fractured layer section (5).

10. A method for testing a horizontal well production profile according to claim 1, characterized in that: The production profile data includes the temperature, pressure and production data of each layer section in the well; the temperature and pressure data of the production layer are directly obtained from the temperature and pressure data recorded by the logging instrument (3), and the temperature and pressure data of the layer section where each logging instrument (3) is located are determined according to the number of each logging instrument (3); the flow data of each production layer is comprehensively judged through the instrument acceleration information and the time when each logging instrument (3) arrives at the vertical well section; then, the pressure recovery data of each production layer section obtained by the logging instrument (3) is combined with the well test analysis method to calculate the fracture parameters and reservoir parameters.

Images