A method for water detection in horizontal wells

Abstract

The present application belongs to the field of petroleum testing, and particularly relates to a method for finding water in a horizontal well. The method comprises a water finding pipe string, one end of the water finding pipe string is sealed, a packer and a window pipe are arranged on the water finding pipe string close to the sealed end of the water finding pipe string, the method is as follows: the water finding pipe string is lowered to the toe or heel perforation section in the well, the setting position of the packer is changed, and the liquid level change of the water finding pipe string per unit time is obtained, the pressure of each position of the perforation section is obtained through the liquid level change, and thus the main water outlet section is obtained. The method has the advantages of rapidness, high efficiency and high accuracy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of oil testing, and particularly relates to a water finding method for horizontal well. BACKGROUND

[0002] With the extension of water injection time, the water content of oil wells in water injection development oilfields will gradually increase, especially in low-permeability and ultra-low-permeability fractured horizontal wells, the transformation scale is large, the number of production sections is large, and after the water breakthrough of oil wells, the water content and water production will increase greatly, which seriously affects the oil production of oil wells, and even directly floods. The conventional water layer identification method mainly includes testing water finding, mechanical water finding, tracer water finding and the like. Among them, the mechanical water finding mainly judges the liquid discharge condition and water content of each section by meansing the packer to seal and then pumping and drawing each section to produce and testing. However, for the section with low production and large water content fluctuation, the testing time is long and not accurate, and for the low-pressure recharge section, the drainage time cannot be predicted, so the testing time is too long or the water section is misjudged. The logging water finding method is a method of analyzing after testing by means of neutron oxygen activation, natural potential, natural gamma, flowmeter and water holding rate meter. First, the basic pumping and drawing or electric submersible pump production drainage measurement is needed; second, whether the logging data after water flooding can reflect the real situation of the reservoir or not; third, the flow of the small flow well cannot be tested; fourth, the produced water and recharge water cannot be identified. The patch tracer method is to lower the tool string combined by the patch tracer short section and the packer into the well in each section, seal each production section by the packer, and then normally produce, the produced water dissolves the patch tracer and carries out the tracer, and then the produced water position and water yield are analyzed by means of wellhead sampling and testing to find water. The method has the following problems: first, the super-long large-diameter tool string needs to be lowered, which not only brings risks to the operation, but also the sealing property of the packer cannot be verified, and if the sealing is not strict, the testing result will be directly affected; second, the long-term sampling and testing analysis not only has a long cycle, but also has a large workload and high cost; third, the pipe outside channeling cannot be identified; fourth, the produced water and recharge water cannot be identified. The effect is not good in the actual application, and deviates greatly from the actual situation.

[0003] At present, the method for finding water mainly includes pumping, testing, sampling and the like, which need to be combined with production, pumping and the like drainage means. Chinese patent application numbers CN202010747159.5, CN201910926530.1, CN201510883078.7 and CN200920246802.5 respectively disclose different water finding methods, but all have the problems of large workload, long testing cycle and low accuracy.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] In order to solve the technical problems in the prior art, the present application provides a water finding method for horizontal well, which has the advantages of rapidness, high efficiency and high accuracy.

[0006] The application comprises the following technical solutions.

[0007] The application relates to a water-finding method for a horizontal well.

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

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

[0010] The water-finding pipe string is lowered to the toe or heel perforation section of the well.

[0011] The first packer and the second packer are set, and the first liquid level of the water-finding pipe string is measured.

[0012] After a unit time, the second liquid level of the water-finding pipe string is measured.

[0013] The liquid level change of the water-finding pipe string is obtained through the first liquid level and the second liquid level.

[0014] The above steps are repeated until the liquid level change of all positions of the perforation section is obtained; the position of the perforation section with the largest liquid level change is the main water outlet section.

[0015] Further, the distance between the two packers is less than or equal to a preset distance.

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

[0017] Further, when the first packer and / or the second packer is set, the setting qualification of the first packer and / or the second packer is tested.

[0018] Further, the testing method of the setting qualification comprises the following steps.

[0019] The first liquid level change height of the water-finding pipe string and the second liquid level change height of the oil pipe are measured through the first packer and / or the second packer.

[0020] The setting qualification is judged according to the change of the first liquid level change height and the second liquid level change height; if the first liquid level change height is equal to the second liquid level change height, the setting is unqualified.

[0021] If the first liquid level change height is not equal to the second liquid level change height, the setting is qualified.

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

[0023] Further, the packer comprises a first packer, and an eye pipe and the first packer are sequentially arranged on the water-finding pipe string extending away from one end of the sealing end, and the method comprises the following steps:

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

[0025] Dividing the perforation section into N sections, and sequentially obtaining the liquid level change of each section:

[0026] Setting the first packer, measuring the first liquid level of the water-finding pipe string; after a unit time, measuring the second liquid level of the water-finding pipe string; obtaining the liquid level change of the water-finding pipe string through the first liquid level and the second liquid level; the liquid level change is obtained through the following formula: ΔL N = L N -L N-1 ;

[0027] The position of the perforation section with the largest liquid level change is the main water production section;

[0028] Wherein: 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, and L0=0.

[0029] Further, the unit time is 30min-60min.

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

[0031] By adopting the technical scheme, the present application has the following advantages:

[0032] 1. The method has the advantages of rapidness, high efficiency and high accuracy.

[0033] 2. The present application separates the horizontal perforation section by double-sealing single-clamping or single-sealing single-clamping, and then obtains the liquid level height in the tubing and the casing by a sound wave method or a physical measurement method, so as to convert the static pressure of each perforation section and the liquid level change per unit time. Without production and swabbing cooperation, and without lowering expensive logging instruments and long-time sampling analysis, the pressure condition and the liquid production condition of each perforation section can be quickly and intuitively judged, and the present application has the advantages of low cost, fast identification and no need of liquid discharge compared with other methods, and has significant advantages in quickly determining the main water production section (high-pressure water production section) of the high-pressure water production horizontal well.

[0034] 3. The water-finding pipe string structure of the present application is simple, and the water-finding method thereof is simple. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of a horizontal well water-finding method according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the water pipe column in an embodiment of the present invention. Figure One ;

[0038] Figure 3 This is a schematic diagram of the structure of the water pipe column in an embodiment of the present invention. Figure Two ;

[0039] In the diagram: 10 - find the water pipe string, 11 - packer, 111 - first packer, 112 - second packer, 12 - eye tube, 20 - oil pipe. Detailed Implementation

[0040] The following description provides many different embodiments or examples for implementing various features of the invention. The elements and arrangements described in the specific examples below are only for concise expression of the invention and are merely examples, not intended to limit the invention.

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

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0043] like Figure 1 As shown, this embodiment provides a method for finding water in a horizontal well, including a water-finding tubing string 10. One end of the water-finding tubing string 10 is sealed, and a packer 11 and a hole tube 12 are provided on the water-finding tubing string 10 near the sealed end. The method is as follows:

[0044] Lower the water-finding string 10 to the toe or heel perforation section in the well, change the setting position of the packer 11, and obtain the liquid level change of the water-finding string 10 per unit time, and the pressure of each position of the perforation section is obtained through the liquid level change, so that the main water production section is obtained.

[0045] The water breakthrough of the horizontal well in the water injection development oilfield is mainly the injected water breakthrough, the pressure of the water production section is high, the high-pressure water production section can be identified by judging the pressure of each section, and the liquid column height of the perforation section indirectly reflects the pressure of the section, therefore, the high-pressure water production 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 application can judge the perforation section with higher liquid level and greater speed, i.e. the high-pressure water production section (main water production section), by sealing the perforation section by the packer, and then testing the liquid level height recovery value and recovery speed of the water-finding string inside and outside of all the perforation sections.

[0046] In some embodiments, as shown in FIG. 1, the packer 11 includes a first packer 111 and a second packer 112, the eye pipe 12 is arranged between the first packer 111 and the second packer 112, and the method includes the following steps: Figure 2 Lowering the water-finding string 10 to the toe or heel perforation section in the well;

[0047] Setting the first packer 111 and the second packer 112, and measuring the first liquid level of the water-finding string 10;

[0048] After a unit time, measuring the second liquid level of the water-finding string 10;

[0049] Obtaining the liquid level change of the water-finding string 10 through the first liquid level and the second liquid level;

[0050] Repeating the above steps until the liquid level change of all positions of the perforation section is obtained; the position of the perforation section with the largest liquid level change is the main water production section.

[0051] In some embodiments, the distance between the two packers 11 is ≤ a preset distance.

[0052] The formation water production is intermittent, and the intermittent time of each formation is different, so after the packer 11 is set, a period of time needs to be waited before measuring the liquid level, and in some embodiments, the unit time is: 30 min to 60 min; this time avoids the reduction of measurement accuracy caused by intermittent water production. It should be noted that the unit time includes but is not limited to this.

[0053]

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

[0055] In some embodiments, the method for testing the setting qualification comprises the following steps:

[0056] measuring the first liquid level change of the water-finding string 10 and the second liquid level change of the tubing 20 by the first packer 111 and / or the second packer 112;

[0057] determining the setting qualification according to the changes of the first liquid level change and the second liquid level change: if the first liquid level change = the second liquid level change, the setting is unqualified;

[0058] if the first liquid level change ≠ the second liquid level change, the setting is qualified.

[0059] In order to improve the accuracy of the measurement, the position of the first packer and / or the second packer is adjusted (i.e. the position of the water-finding string 10 is moved) when the setting is unqualified, and the setting is performed again.

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

[0061] In some embodiments, as shown in FIG. 1, the packer 11 comprises the first packer 111, and the tubing 12 and the first packer 111 are sequentially arranged on the water-finding string 10 extending from one end away from the sealing end, and the method comprises the following steps: Figure 3

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

[0063] S200: dividing the perforation section into N sections, and sequentially obtaining the liquid level change of each section:

[0064] S300: setting the first packer 111, measuring the first liquid level of the water-finding string 10, measuring the second liquid level of the water-finding string 10 after a unit time, obtaining the liquid level change of the water-finding string 10 by the first liquid level and the second liquid level, and the liquid level change is obtained by the following formula: N = L N - L N-1 ; the position of the perforation section with the largest liquid level change is the main water outlet section;

[0065] wherein: 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, and L0=0.​

[0066] In some embodiments, the unit time is 30-60 minutes.

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

[0068] Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood that the technical solutions recorded in the foregoing embodiments can still be modified, or some of the technical features can be replaced by equivalents, by those of ordinary skill in the art, without departing from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for finding water in a horizontal well, characterized in that, The method includes a water-finding pipe string, one end of which is sealed. A packer and an eyelet are installed on the water-finding pipe string near the sealed end. The water-finding tubing string is lowered to the toe or heel perforation section in the well, the packer setting position is changed, and the change in the liquid level of the water-finding tubing string per unit time is obtained. The pressure at each position of the perforation section is obtained through the change in the liquid level, thereby obtaining the main water-producing section. The packer includes a first packer and a second packer, and the eye tube is disposed between the first packer and the second packer. The method includes the following steps: Lower the water-finding tubing string to the toe or heel perforation section of the well; Set the first and second packers, and measure the first liquid level in the water-finding tube column; After each unit of time, measure the second liquid level in the water-finding tube column; The changes in the liquid level of the water-finding tube column are obtained by measuring the first and second liquid levels. Repeat the above steps until the liquid level changes at all locations of the perforation section are obtained; the perforation section with the largest liquid level change is the main water outlet section.

2. The method for finding water in a horizontal well as described in claim 1, characterized in that, The distance between the two packers is less than or equal to the preset distance.

3. The method for finding water in a horizontal well as described in claim 1, characterized in that, The unit of time is 30 min to 60 min.

4. The method for finding water in a horizontal well as described in claim 1, characterized in that, When setting the first packer and / or the second packer, the setting of the first packer and / or the second packer shall be tested to ensure that the setting is qualified.

5. A method for finding water in a horizontal well as described in claim 4, characterized in that, The test method for determining the set seal qualification includes the following steps: By using the first packer and / or the second packer, the first fluid level change height of the water-finding tubing and the second fluid level change height of the tubing are measured. The setting seal is judged to be qualified based on the change in the first liquid level height and the change in the second liquid level height: if the change in the first liquid level height equals the change in the second liquid level height, then the setting seal is unqualified. If the change in the first liquid level is not equal to the change in the second liquid level, then the sealing is qualified.

6. The method for finding water in a horizontal well as described in claim 1, characterized in that, The first liquid level is obtained by acoustic wave method or physical measurement method; and / or the second liquid level is obtained by acoustic wave method or physical measurement method.

7. A method for finding water in a horizontal well as described in claim 1, characterized in that, The packer includes a first packer, and an eye tube and the first packer are sequentially arranged on the water-finding pipe string extending towards the end away from the sealing end. The method includes the following steps: Lower the water-finding tubing string to the toe or heel perforation section of the well; Divide the perforation section into N segments, and obtain the liquid level changes in each segment sequentially: Set the first packer and measure the first liquid level in the water-finding tube string; after a unit time, measure the second liquid level in the water-finding tube string; obtain the liquid level change in the water-finding tube string through the first and second liquid levels; the liquid level change is obtained by the following formula: The section of the perforation where the liquid level changes most is the main water outlet section. in: , n is a positive integer. .

8. A method for finding water in a horizontal well as described in claim 7, characterized in that, The unit of time is 30 min to 60 min.

9. A method for finding water in a horizontal well as described in claim 1, characterized in that, The packer is Y211, Y111 or Y521.

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