Downhole temperature and pressure testing process

Abstract

The invention relates to an underground temperature and pressure testing process, 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; step 2, data acquisition; 3, the logging instrument is recycled; and 4, explaining temperature and pressure profiles. The logging instrument and the drilling nipple are combined, the problems that in the drilling process, underground temperature and pressure testing is difficult and cost is high are solved, the underground temperature and pressure testing requirement in the drilling process is met, and the advantages of being low in construction cost and simple and convenient in testing technology are achieved.

Description

Technical Field

[0001] The invention relates to a downhole temperature and pressure testing process, belonging to the technical field of oil and gas field testing. Background Art

[0002] Drilling is an important part of geological exploration and mineral deposit development, and is the only way to connect oil and gas layers to the ground to form oil and gas production. Accurately understanding the temperature and pressure conditions downhole during drilling plays an important guiding role in correctly evaluating the working state of the drilling fluid and reasonably determining the density ratio of the drilling fluid; downhole pressure gauges and downhole annular pressure monitors (PWD) are currently the only two instruments that can achieve downhole pressure monitoring, but downhole pressure gauges can only read data after drilling, with a long delay, and cannot truly reflect the current downhole dynamics, while downhole annular pressure monitors are expensive and cannot achieve low-cost drilling. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention discloses a downhole temperature and pressure testing process, which meets the testing requirements of downhole temperature and pressure during drilling and has the advantages of low construction cost and simple testing process.

[0004] The technical solution adopted by the present invention is a downhole temperature and pressure testing process, and the specific steps are as follows:

[0005] Step 1: Preparation before testing;

[0006] Step 2: data collection;

[0007] Step 3, recovering the logging tool;

[0008] Step 4. Interpret the temperature and pressure profiles.

[0009] Furthermore, the step 1 specifically includes programming the logging instrument before entering the well and installing the logging instrument on the drill string short section.

[0010] Furthermore, in the step 1, the logging instrument is programmed, and the sampling period of the instrument is set according to the drilling plan; each logging instrument is numbered, and a corresponding well number and lowering position information are assigned, and this information is written into the memory of the logging instrument.

[0011] Furthermore, the logging instrument is fixed on the drill string short section by means of a soluble fixing clamp and a soluble fixing screw, and the installation position of the logging instrument is close to the drill bit of the drill string short section.

[0012] Furthermore, screw holes are provided at both ends of the soluble fixing clamp, and the soluble fixing screws are passed through the screw holes and installed on the drill string short section.

[0013] Furthermore, the soluble fixing clamp and the soluble fixing screw are made of aluminum-magnesium alloy or magnesium-lithium alloy.

[0014] Furthermore, the step 2 specifically includes starting drilling according to the drilling design requirements, lowering the logging instrument into the well along with the drill string short section, and the logging instrument reaches a predetermined test depth during the drilling process; after the logging instrument is lowered into the well along with the drill string short section, data is collected according to the set sampling period to record the temperature and pressure downhole.

[0015] Furthermore, the step three specifically includes gradually dissolving the soluble fixing clamp and the soluble fixing screw to be used to fix the logging instrument in the well fluid, so that the logging instrument becomes free and returns to the ground from the annulus as the drilling fluid circulates. The logging instrument records its own acceleration and attitude data through the acceleration sensor and the gyro sensor, thereby completing the recovery of the logging instrument.

[0016] Furthermore, the step 4 specifically includes replaying and reading the test data in the memory of the logging instrument through a computer, identifying the number of the logging instrument, and obtaining the downhole temperature, pressure and acceleration data measured by the logging instrument; determining the depth change process of the logging instrument during the drilling process according to the drill string condition, the drilling record and the position of the logging instrument fixed on the drill string short section, and obtaining the temperature and pressure profile data during the drilling process by corresponding the temperature and pressure data measured by the logging instrument to the downhole depth;

[0017] The position curve of the logging instrument during its circulation from downhole to the wellhead is obtained based on the position of the logging instrument on the drill string, the time it takes for the logging instrument to return to the ground along with the drilling fluid circulation, and the acceleration data of the logging instrument itself. The temperature and pressure profile of the logging instrument circulating out of the well is obtained by combining the temperature and pressure data measured during the logging instrument's return process.

[0018] The invention discloses a downhole temperature and pressure testing process, which has the beneficial effect that the invention solves the problem of difficulty and high cost in testing downhole temperature and pressure during drilling by combining a logging instrument with a drilling pup joint, meets the testing requirements of downhole temperature and pressure during drilling, and has the effects of low construction cost and simple testing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] Figure 1 The figure shows a schematic diagram of the connection between the well logging tool and the drill string short section in Example 1;

[0021] Figure 2 Shown Figure 1 A side view schematic diagram of

[0022] Figure 3 The figure shows a schematic diagram of the logging instrument in Example 1 being lowered into the well along with the drill string and the circulation of the drilling fluid being returned along with the drilling.

[0023] Reference numerals in the figure: 1, logging instrument; 2, drill string short section; 3, soluble fixing clamp; 4, soluble fixing screw; 5, drill bit; 6, logging instrument in free state.

[0024] Specific implementation methods

[0025] 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.

[0026] In order to further understand the content of the present invention, the present invention is further described below in conjunction with specific implementation methods.

[0027] Example 1: Figures 1 to 3 As shown, a downhole temperature and pressure testing process specifically includes:

[0028] Step 1, preparatory work before testing; specifically, programming the logging instrument 1 before entering the well, setting the sampling period of the instrument according to the drilling plan; numbering each logging instrument 1, assigning the corresponding well number and lowering position information, and writing this information into the memory of the logging instrument 1.

[0029] The logging instrument 1 is placed on the side wall of the drill string short section 2, the soluble fixing clamp 3 is sleeved on the outside of the logging instrument 1, and the soluble fixing screw 4 is installed on the drill string short section 2 through the screw hole, so that the logging instrument 1 is closely fitted with the drill string short section 2. The installation position of the logging instrument 1 is as close as possible to the drill bit 5 of the drill string short section 2. The material of the soluble fixing clamp 3 and the soluble fixing screw 4 is aluminum-magnesium alloy. It should be noted that the soluble fixing clamp 3 and the soluble fixing screw 4 meet the requirements that the density is greater than the density of the drilling fluid and they are dissolved in the downhole electrolyte environment.

[0030] Step 2, data collection; specifically, starting drilling according to the drilling design requirements, the logging instrument 1 is lowered into the well along with the drill string short section 2, and the logging instrument 1 reaches the predetermined test depth during the drilling process; the logging instrument 1 is in a dormant state from the time of being lowered into the well until the drill bit 5 reaches the target drilling depth, saving power and storage space of the logging instrument 1; after the predetermined time is reached, the logging instrument 1 starts to collect the temperature and downhole pressure of the drilling fluid at the downhole drill bit 5.

[0031] Step three, recovering the logging instrument 1; specifically, the soluble fixing clamp 3 and the soluble fixing screw 4 to be fixed on the logging instrument 1 are gradually dissolved in the well fluid, and the logging instrument 1 is separated from the drill string short section 2, thereby becoming a free logging instrument 6, which returns to the ground from the annulus with the circulation of the drilling fluid. The logging instrument 1 records its own acceleration and attitude data through the acceleration sensor and the gyro sensor, and the recovery of the logging instrument 1 is completed.

[0032] Step 4, interpreting the temperature and pressure profile. Specifically, the test data in the memory of the logging instrument 1 is played back and read out by a computer, and the serial number of the logging instrument 1 is identified to obtain the downhole temperature, pressure and acceleration data measured by the logging instrument 1; the depth change process of the logging instrument 1 during drilling is determined according to the drill string conditions, drilling records and the position of the logging instrument 1 fixed on the drill string short section 2, and the temperature and pressure data measured by the logging instrument 1 are matched with the downhole depth to obtain the temperature and pressure profile data during drilling;

[0033] The position curve of the logging instrument 1 during the circulation from downhole to the wellhead is obtained based on the position of the logging instrument 1 on the drill string, the time when the logging instrument 1 returns to the ground along with the drilling fluid circulation, and the acceleration data of the logging instrument 1 itself. The temperature and pressure profile of the logging instrument 1 circulating out of the well is obtained by combining the temperature and pressure data measured during the return process of the logging instrument 1.

[0034] 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 downhole temperature and pressure testing process, characterized in that: The specific steps are as follows: Step 1: Preparation before testing; Step 2: data collection; Step 3, recovering the logging tool (1); Step 4. Interpret the temperature and pressure profiles.

2. A downhole temperature and pressure testing process according to claim 1, characterized in that: Step one specifically includes programming the well logging instrument (1) before entering the well and installing the well logging instrument (1) on the drill string short section (2).

3. A downhole temperature and pressure testing process according to claim 2, characterized in that: In step 1, the logging instrument (1) is programmed and the sampling period of the instrument is set according to the drilling plan; each logging instrument (1) is numbered, and a corresponding well number and lowering position information are assigned, and this information is written into the memory of the logging instrument (1).

4. A downhole temperature and pressure testing process according to claim 2, characterized in that: The logging instrument (1) is fixed on the drill string short section (2) through a soluble fixing clamp (3) and a soluble fixing screw (4). The installation position of the logging instrument (1) is close to the drill bit (5) of the drill string short section (2).

5. A downhole temperature and pressure testing process according to claim 4, characterized in that: Screw holes are arranged at both ends of the soluble fixing clamp (3), and the soluble fixing screws (4) pass through the screw holes to press the well logging instrument (3) tightly onto the drill string short section (2).

6. A downhole temperature and pressure testing process according to claim 5, characterized in that: The soluble fixing clamp (3) and the soluble fixing screw (4) have a density greater than that of the drilling fluid and are soluble in an underground electrolyte environment.

7. A downhole temperature and pressure testing process according to claim 6, characterized in that: The material of the soluble fixing clamp (3) and the soluble fixing screw (4) is aluminum-magnesium alloy or magnesium-lithium alloy.

8. A downhole temperature and pressure testing process according to claim 1, characterized in that: Step 2 specifically includes starting drilling according to the drilling design requirements, lowering the well logging instrument (1) into the well along with the drill string short section (2), and the well logging instrument (1) reaches a predetermined test depth during the drilling process; after the well logging instrument (1) is lowered into the well along with the drill string short section (2), data is collected according to a set sampling period to record the temperature and pressure downhole.

9. A downhole temperature and pressure testing process according to claim 1, characterized in that: Step three specifically includes gradually dissolving the soluble fixing clamp (3) and the soluble fixing screw (4) of the logging instrument (1) to be fixed in the drilling fluid, and the logging instrument (1) becomes free and returns to the ground from the annulus as the drilling fluid circulates. The logging instrument (1) records its own acceleration and attitude data through the acceleration sensor and the gyro sensor, and the recovery of the logging instrument (1) is completed.

10. A downhole temperature and pressure testing process according to claim 1, characterized in that: Step 4 specifically includes replaying and reading the test data in the memory of the logging instrument (1) through a computer, identifying the serial number of the logging instrument (1), and obtaining the downhole temperature, pressure and acceleration data measured by the logging instrument (1); determining the depth change process of the logging instrument (1) during the drilling process according to the drill string condition, the drilling record and the position of the logging instrument (1) fixed on the drill string short section (2), and obtaining the temperature and pressure profile data during the drilling process by correlating the temperature and pressure data measured by the logging instrument (1) with the downhole depth; The position curve of the logging instrument (1) during the process of circulating from the downhole to the wellhead is obtained based on the position of the logging instrument (1) on the drill string, the time when the logging instrument (1) returns to the ground along with the drilling fluid circulation, and the acceleration data of the logging instrument (1) itself. The temperature and pressure profile of the logging instrument (1) circulating out of the well is obtained by combining the temperature and pressure data measured during the return process of the logging instrument (1).

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