Horizontal well water exploration method

Abstract

The invention belongs to the field of petroleum testing, and particularly relates to a horizontal well water exploration method. Comprising a water exploration tubular column, one end of the water exploration tubular column is sealed, a packer and a hole pipe are arranged on the water exploration tubular column close to the sealed end of the water exploration tubular column, and the method comprises the steps that the water exploration tubular column is lowered to a toe or heel perforation section in a well, the setting position of the packer is changed, and the liquid level change of the water exploration tubular column in unit time is obtained; and the pressure of each position of the perforation section is obtained through the change of the liquid level, so that a main water outlet section is obtained. The method has the advantages of rapidness, high efficiency and high accuracy.

Description

Technical Field

[0001] The invention belongs to the field of petroleum testing, and in particular relates to a method for finding water in a horizontal well. Background Art

[0002] As the water injection time continues, the water content of the oil wells will gradually increase in the water injection development of the oil field, especially for low-permeability and ultra-low-permeability fractured horizontal wells. The transformation scale is large and the number of production sections is large. After the water appears in the oil wells, the water content and water production will increase significantly, seriously affecting the oil production of the oil wells, and even directly flooding. Conventional methods for identifying water-producing layers mainly include testing for water, mechanical water finding, and tracer water finding. Among them, mechanical water finding mainly determines the liquid output and water content of each section by pumping out the production section after the packer is stuck and testing. However, for sections with low production and large water content fluctuations, the test time is long and inaccurate. For low-pressure reinjection sections, the drainage time cannot be predicted, so either the test time is too long or it is mistakenly identified as a water-producing section. The logging method for finding water is a method of post-test analysis through neutron oxygen activation, natural potential, natural gamma, flow meter, water holdup meter, etc. First, it is necessary to cooperate with the pumping or electric submersible pump production and drainage to coordinate the measurement; second, whether the logging data after flooding can reflect the real situation of the reservoir rather than the false appearance after flooding; third, the flow of small flow wells cannot be tested; fourth, it is impossible to distinguish between produced water and reinjection water. The patch tracer method is to lower the tool string of short joints and packers with patch tracers into the well section by section, and then pass the packer to the production section of the packer, and then produce normally. The produced water flows through the tracer patch to dissolve and bring out the tracer, and then the wellhead is sampled and tested to analyze the water outlet position and water output to find water. This method requires the insertion of an ultra-long and long diameter tool string, which not only brings risks to the operation, but also the sealing of the packer cannot be verified. If the seal is not tight, it will directly affect the test results; second, long-term sampling and testing analysis not only has a long cycle, but also a large workload and high cost; third, the pipe can not be identified; fourth, it is impossible to distinguish between produced water and reinjection water. And the effect is not good in actual field application, and it deviates greatly from the actual situation.

[0003] At present, the methods used to find water are mainly through pumping, analysis, testing, etc., which all need to be coordinated with production, pumping and other drainage methods. Chinese patent application numbers CN202010747159.5, CN201910926530.1, CN201510883078.7, and CN200920246802.5 respectively disclose different methods for finding water, but all have problems such as large workload, long testing cycle, and low accuracy.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a method for finding water in a horizontal well, which has the advantages of being fast, efficient and highly accurate.

[0006] The present invention includes the following technical solutions:

[0007] The present invention provides a method for finding water in a horizontal well, characterized in that it comprises a water finding pipe column, one end of the water finding pipe column is sealed, and a packer and an eye tube are arranged on the water finding pipe column near the sealed end of the water finding pipe column. The method comprises:

[0008] The water-finding string is lowered to the toe or heel perforation section in the well, the packer setting position is changed, and the change of the liquid level in the water-finding string per unit time is obtained. The pressure at each position of the perforation section is obtained through the change of the liquid level, thereby obtaining the main water-yielding section.

[0009] Further, the packer comprises a first packer and a second packer, the eye tube is arranged between the first packer and the second packer, and the method comprises the following steps:

[0010] Lower the water-finding string to the toe or heel perforation section in the well;

[0011] Set the first packer and the second packer, and measure the first liquid level of the water finding string;

[0012] After a unit time, measure the second liquid level of the water-finding column;

[0013] Obtaining the liquid level change of the water-finding column through the first liquid level and the second liquid level;

[0014] Repeat the above steps until the liquid level changes at all positions of the perforation section are obtained; the perforation section position with the largest liquid level change is the main water discharge section.

[0015] Further, the distance between the two packers is ≤ a preset distance.

[0016] Furthermore, the unit time is: 30min to 60min.

[0017] Further, when setting the first packer and / or the second packer, it is tested whether the setting of the first packer and / or the second packer is qualified.

[0018] Furthermore, the test method for setting the seal qualified includes the following steps:

[0019] By placing the first packer and / or the second packer, a first liquid level change height of the water-finding string and a second liquid level change height of the oil pipe are measured;

[0020] The setting is judged to be qualified according to the changes of the first liquid level change height and the second liquid level change height: if the first liquid level change height = the second liquid level change height, the setting is unqualified;

[0021] If the first liquid level change height ≠ the second liquid level change height, the sealing is qualified.

[0022] Furthermore, the first liquid level is obtained by an acoustic wave method or a physical measurement method; and / or the second liquid level is obtained by an acoustic wave method or a physical measurement method.

[0023] Furthermore, the packer includes a first packer, and an eye tube and the first packer are sequentially arranged on the water finding pipe string extending toward an end away from the sealing end. The method includes the following steps:

[0024] Lower the water-finding string to the toe or heel perforation section in the well;

[0025] The perforation section is divided into N sections, and the liquid level changes of each section are obtained in turn:

[0026] The first packer is set and the first liquid level of the water-finding string is measured; after a unit time, the second liquid level of the water-finding string is measured; the liquid level change of the water-finding string is obtained through the first liquid level and the second liquid level; the liquid level change is obtained by the following formula: Δ N =L N -L N-1 ;

[0027] The perforation section where the liquid level changes the most is the main water discharge section;

[0028] Where: L N =the second liquid level of the Nth section - the first liquid level of the Nth section, N∈(1,2,、、、,n), n is a positive integer, L0=0.

[0029] Furthermore, the unit time is: 30min to 60min.

[0030] Furthermore, the packer is Y211, Y111 or Y521.

[0031] By adopting the above technical solution, the present invention has the following advantages:

[0032] 1. The method of the present invention has the advantages of being fast, efficient and highly accurate.

[0033] 2. The present invention separates the horizontal perforation sections into sections by double-seal single card or single-seal single card, and then obtains the liquid level height in the tubing and casing by acoustic wave, physical measurement and other methods, so as to convert the static pressure of each perforation section and the change of liquid level per unit time. It does not require production and pumping coordination, nor does it require the insertion of expensive logging instruments and long-term sampling and analysis. It can quickly and intuitively determine the pressure and liquid production conditions of each perforation section. Compared with other methods, it has the advantages of low cost, fast identification, and no need for drainage. It has significant advantages for quickly determining the main water-producing section (high-pressure water-producing section) of high-pressure water-producing horizontal wells.

[0034] 3. The water-finding pipe column of the present invention has a simple structure, and the water-finding method thereof is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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 work.

[0036] Figure 1 This is a flow chart of a method for finding water in a horizontal well in an embodiment of the present invention;

[0037] Figure 2 The structure of the water-finding column in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0038] Figure 3 The structure of the water-finding column in the embodiment of the present invention is shown in FIG. Figure 2 ;

[0039] In the figure: 10-water finding pipe column, 11-packer, 111-first packer, 112-second packer, 12-eye tube, 20-oil pipe. DETAILED DESCRIPTION

[0040] The following description provides many different embodiments or examples for implementing different features of the present invention. The components and arrangements described in the following specific examples are only used to simplify the present invention and are only used as examples, not to limit the present invention.

[0041] In the description of the present invention, the terms "first" and "second" are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 part of the embodiments of the present invention, not all of the embodiments. 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.

[0043] like Figure 1 As shown, this embodiment provides a method for finding water in a horizontal well, including a water finding pipe string 10, one end of the water finding pipe string 10 is sealed, and a packer 11 and an eye tube 12 are arranged on the water finding pipe string 10 near the sealed end of the water finding pipe string 10. The method is:

[0044] The water-finding string 10 is lowered to the toe or heel perforation section in the well, the setting position of the packer 11 is changed, and the liquid level change of the water-finding string 10 per unit time is obtained. The pressure at each position of the perforation section is obtained through the liquid level change, thereby obtaining the main water-yielding section.

[0045] The water that appears in the horizontal well of the water injection development oil field is mainly the injected water. The pressure of the water outlet section is high. The high-pressure water outlet section can be identified by judging the pressure of each section, and the height of the liquid column in the perforation section indirectly reflects the pressure of this section. Therefore, the high-pressure water outlet section can be identified by testing the liquid level recovery height of the perforation section, and the main liquid production section can be identified by the liquid level recovery speed. The present invention isolates the perforation section section by section through the packer, and then tests the liquid level recovery value and recovery speed inside and outside the water-finding pipe column of all the perforation sections respectively to judge the perforation section with higher liquid level height and higher speed, that is, the high-pressure water outlet section (main water outlet section).

[0046] In some embodiments, Figure 2 As shown, the packer 11 includes a first packer 111 and a second packer 112, and the eye tube 12 is arranged between the first packer 111 and the second packer 112. The method includes the following steps:

[0047] Lowering the water finding pipe string 10 to the toe or heel perforation section in the well;

[0048] Setting the first packer 111 and the second packer 112, and measuring the first liquid level of the water finding string 10;

[0049] After the unit time, the second liquid level of the water finding pipe column 10 is measured;

[0050] Obtaining the liquid level change of the water-finding string 10 through the first liquid level and the second liquid level;

[0051] Repeat the above steps until the liquid level changes at all positions of the perforation section are obtained; the perforation section position with the largest liquid level change is the main water discharge section.

[0052] In some embodiments, the distance between the two packers 11 is less than or equal to a preset distance.

[0053] The formation water is intermittent, and the intermittent time of each formation is different, so after the packer 11 is set, it is necessary to wait for a period of time before measuring the liquid level. In some embodiments, the unit time is: 30min to 60min; this time avoids the reduction of measurement accuracy due to intermittent water production. It should be noted that the unit time includes but is not limited to this.

[0054] In some embodiments, when setting the first packer 111 and / or the second packer 112, the setting of the first packer 111 and / or the second packer 112 is tested to be qualified. Based on this, the accuracy of the measurement can be improved.

[0055] In some embodiments, the test method for setting qualified includes the following steps:

[0056] By placing the first packer 111 and / or the second packer 112, a first liquid level change height of the water finding string 10 and a second liquid level change height of the oil pipe 20 are measured;

[0057] The setting is judged to be qualified according to the changes of the first liquid level change height and the second liquid level change height: if the first liquid level change height = the second liquid level change height, the setting is unqualified;

[0058] If the first liquid level change height ≠ the second liquid level change height, the sealing is qualified.

[0059] In order to improve the accuracy of the measurement, in the case of unqualified setting, the position of the first setting device and / or the second setting device is adjusted (ie, the position of the water finding pipe string 10 is moved), and the setting is performed again.

[0060] In some embodiments, the first liquid level is obtained by an acoustic wave method or a physical measurement method; and / or the second liquid level is obtained by an acoustic wave method or a physical measurement method.

[0061] In some embodiments, Figure 3 As shown, the packer 11 includes a first packer 111, and an eye tube 12 and the first packer 111 are sequentially arranged on the water finding pipe string 10 extending toward an end away from the sealing end. The method includes the following steps:

[0062] S100: lowering the water finding pipe string 10 to the toe or heel perforation section in the well;

[0063] S200: Divide the perforation section into N sections, and obtain the liquid level change of each section in turn:

[0064] S300: Set the first packer 111, measure the first liquid level of the water-finding string 10; after a unit time, measure the second liquid level of the water-finding string 10; obtain the liquid level change of the water-finding string 10 through the first liquid level and the second liquid level; the liquid level change is obtained by the following formula: Δ N =L N -L N-1 ; The perforation section where the liquid level changes the most is the main water discharge section;

[0065] Where: L N =the second liquid level of the Nth section - the first liquid level of the Nth section, N∈(1,2,、、、,n), n is a positive integer, L0=0.

[0066] In some embodiments, the unit time is: 30min to 60min.

[0067] In some embodiments, the packer is Y211, Y111 or Y521, etc.

[0068] 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 make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for finding water in a horizontal well, characterized in that: The invention comprises a water finding pipe column, one end of which is sealed, and a packer and an eye tube are arranged on the water finding pipe column near the sealed end of the water finding pipe column. The method comprises: The water-finding string is lowered to the toe or heel perforation section in the well, the packer setting position is changed, and the change of the liquid level in the water-finding string per unit time is obtained. The pressure at each position of the perforation section is obtained through the change of the liquid level, thereby obtaining the main water-yielding section.

2. A method for finding water in a horizontal well according to claim 1, characterized in that: The packer comprises a first packer and a second packer, the eye tube is arranged between the first packer and the second packer, and the method comprises the following steps: Lower the water-finding string to the toe or heel perforation section in the well; Set the first packer and the second packer, and measure the first liquid level of the water finding string; After a unit time, measure the second liquid level of the water-finding column; Obtaining the liquid level change of the water-finding column through the first liquid level and the second liquid level; Repeat the above steps until the liquid level changes at all positions of the perforation section are obtained; the perforation section position with the largest liquid level change is the main water discharge section.

3. A method for finding water in a horizontal well as claimed in claim 2, characterized in that: The distance between the two packers is ≤ the preset distance.

4. A method for finding water in a horizontal well as claimed in claim 2, characterized in that: The unit time is: 30min to 60min.

5. A method for finding water in a horizontal well as claimed in claim 2, characterized in that: When setting the first packer and / or the second packer, the setting of the first packer and / or the second packer is tested to be qualified.

6. A method for finding water in a horizontal well as claimed in claim 5, characterized in that: The test method for setting seal qualification comprises the following steps: By placing the first packer and / or the second packer, a first liquid level change height of the water-finding string and a second liquid level change height of the oil pipe are measured; The setting is judged to be qualified according to the changes of the first liquid level change height and the second liquid level change height: if the first liquid level change height = the second liquid level change height, the setting is unqualified; If the first liquid level change height ≠ the second liquid level change height, the sealing is qualified.

7. A method for finding water in a horizontal well as claimed in claim 2, characterized in that: The first liquid level is obtained by an acoustic wave method or a physical measurement method; and / or the second liquid level is obtained by an acoustic wave method or a physical measurement method.

8. A method for finding water in a horizontal well according to claim 1, characterized in that: The packer comprises a first packer, and an eye tube and the first packer are sequentially arranged on the water finding pipe string extending toward an end away from the sealing end. The method comprises the following steps: Lower the water-finding string to the toe or heel perforation section in the well; The perforation section is divided into N sections, and the liquid level changes of each section are obtained in turn: The first packer is set and the first liquid level of the water-finding string is measured; after a unit time, the second liquid level of the water-finding string is measured; the liquid level change of the water-finding string is obtained through the first liquid level and the second liquid level; the liquid level change is obtained by the following formula: Δ N =L N -L N-1 ; The perforation section where the liquid level changes the most is the main water discharge section; Where: L N =the second liquid level of the Nth section - the first liquid level of the Nth section, N∈(1,2,、、、,n), n is a positive integer, L0=0.

9. A method for finding water in a horizontal well according to claim 8, characterized in that: The unit time is: 30min to 60min.

10. A method for finding water in a horizontal well according to claim 1, characterized in that: The packer is Y211, Y111 or Y521.

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