阅读说明：本技术 膨胀体和砾岩储层改造方法 (Expansion body and conglomerate reservoir transformation method ) 是由 孔垂显 常天全 张广清 蒋庆平 高阳 陈栋梁 陈磊 李胜 卢志远 邱子刚 徐后伟 于 2020-04-29 设计创作，主要内容包括：本发明提供了一种膨胀体和砾岩储层改造方法。其中,膨胀体包括：可变形外层；可变形内层,可变形内层设置于可变形外层的内部,可变形内层的内部具有容纳腔；膨胀剂,设置在容纳腔。本申请的技术方案有效地解决了相关技术中的水力压裂效果差的问题。(The invention provides an expansion body and a conglomerate reservoir transformation method. Wherein, the inflation body includes: a deformable outer layer; the deformable inner layer is arranged inside the deformable outer layer, and an accommodating cavity is formed inside the deformable inner layer; and the expanding agent is arranged in the accommodating cavity. The technical scheme of the application effectively solves the problem of poor hydraulic fracturing effect in the related art.)

1. An expansion body, comprising:

a deformable outer layer (10);

a deformable inner layer (20), the deformable inner layer (20) being arranged inside the deformable outer layer (10), the deformable inner layer (20) having a receiving cavity inside;

an expanding agent (30) disposed in the receiving cavity.

2. Expansion body according to claim 1, characterized in that said deformable outer layer (10) is made of rubber and said deformable inner layer (20) is made of mylar.

3. Expansion body according to claim 1, characterized in that the main components of the expansion agent (30) are calcium oxide and a catalyst.

4. Expansion body according to claim 1, characterized in that said expansion body (1) further comprises water arranged inside said containment chamber, said expanding agent (30) and said water being present in a mass ratio of 11: 2.

5. expansion body according to claim 1, characterized in that the expansion body (1) is a deformable sphere.

6. A conglomerate reservoir reconstruction method employing an expansion body (1) according to any one of claims 1 to 5, characterized in that it comprises the following steps:

step S10: forming an initial fracture (40) within the formation and injecting proppant;

step S20: manufacturing an expansion body (1);

step S30: mixing a plurality of expansion bodies (1) into a first fracturing fluid and injecting the first fracturing fluid into an initial fracture (40);

step S40: and causing the interior of the expansion body (1) to generate hydration reaction for a preset time, expanding and propping the initial crack (40) to form a new crack (41).

7. A conglomerate reservoir reconstruction method according to claim 6, characterized in that, in said step S20, the production of said expansion body (1) comprises the steps of:

a deformable inner layer (20) is made of a polyester film and forms the containing cavity, and an injection port is formed in the deformable inner layer (20);

mixing a swelling agent (30) and water, and injecting the mixture into the accommodating cavity through the injection port;

placing the deformable inner layer (20) into the heated liquid rubber and forming the liquid rubber into a deformable outer layer (10) that surrounds the deformable inner layer (20).

8. A conglomerate reservoir reconstruction method according to claim 6, characterized in that in said step S10, said initial fracture (40) is formed in a fracturing manner by means of a second fracturing fluid, said proppant being mixed into the second fracturing fluid, and in said step S30, the volume ratio of said expanded body (1) to said first fracturing fluid is 1: 9.

9. A conglomerate reservoir modification method according to claim 6, wherein the predetermined time is between 6 and 15 hours.

10. A conglomerate reservoir reconstruction method according to claim 6, characterized in that portions of said plurality of expansion bodies (1) are in abutment with fracture walls of said initial fracture (40).

Technical Field

The invention relates to the field of petroleum engineering, in particular to a method for modifying an expansion body and a conglomerate reservoir.

Background

With the progress of science and technology and the development of times, the demand for energy resources represented by petroleum is increasing at home and abroad. The conglomerate reservoir is used as one of important storage media of the oil and gas reservoir and has important development value and research significance.

Hydraulic fracturing has gained widespread use as an efficient means of reservoir production. In the related art, hydraulic fracturing is applied to the exploitation of conglomerate reservoirs, and the morphology and behavior of hydraulic fractures greatly influence the fracturing effect and oil and gas yield. Besides the gravel surrounding and gravel penetrating actions in the conglomerate reservoir, hydraulic fractures can also have a crack stopping phenomenon when large gravel is met, so that the hydraulic fracturing effect is not ideal.

Disclosure of Invention

The invention mainly aims to provide an expansion body and conglomerate reservoir transformation method to solve the problem of poor hydraulic fracturing effect in the related art.

In order to achieve the above object, according to one aspect of the present invention, there is provided an expansion body comprising: a deformable outer layer; the deformable inner layer is arranged inside the deformable outer layer, and an accommodating cavity is formed inside the deformable inner layer; and the expanding agent is arranged in the accommodating cavity.

Furthermore, the deformable outer layer is made of rubber, and the deformable inner layer is made of a polyester film.

Further, the main components of the expanding agent are calcium oxide and a catalyst.

Further, the expansion body also comprises water arranged in the accommodating cavity, and the mass ratio of the expansion agent to the water is 11: 2.

further, the expansion body is a deformable sphere.

According to another aspect of the present invention, there is provided a conglomerate reservoir modification method, using the expansion body described above, comprising the steps of: step S10: forming an initial fracture in the formation and injecting proppant; step S20: manufacturing an expansion body; step S30: mixing a plurality of expansion bodies into a first fracturing fluid and injecting the first fracturing fluid into an initial fracture; step S40: and carrying out hydration reaction in a preset time in the expansion body, expanding and propping the initial crack to form a new crack.

Further, in step S20, the manufacturing of the expansion body includes the steps of: manufacturing a deformable inner layer by using a polyester film and forming an accommodating cavity, wherein the deformable inner layer is provided with an injection port; mixing the expanding agent and water, and injecting the mixture into the accommodating body through the injection port; and putting the deformable inner layer into the heated liquid rubber and enabling the liquid rubber to form a deformable outer layer wrapping the deformable inner layer.

Further, in step S10, an initial fracture is formed in a fracturing manner by a second fracturing fluid into which a proppant is mixed, and in step S30, the volume ratio of the expanded body to the first fracturing fluid is 1: 9.

Further, the predetermined time is between 6 hours and 15 hours.

Further, portions of the plurality of dilatant bodies abut the fracture walls of the initial fracture.

By applying the technical scheme of the invention, the expansion body comprises the deformable inner layer and the deformable outer layer, the accommodating cavity is formed in the deformable inner layer, the accommodating cavity is filled with the expanding agent, and when the expanding agent begins to expand, the volume of the expansion body can be increased. When the expansion body is placed in the crack, the expansion body increases in volume to prop the crack, so that the crack is further enlarged. Therefore, the technical scheme of the application effectively solves the problem of poor hydraulic fracturing effect in the related art.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic sectional view of an embodiment of an expansion body according to the invention;

FIG. 2 shows a schematic cross-sectional view of the expansion body of FIG. 1 in a compressed state;

FIG. 3 shows a schematic cross-sectional view of the expansion body of FIG. 1 in a fracture; and

figure 4 shows a schematic flow diagram of an embodiment of a conglomerate reservoir reconstruction method according to the invention.

Wherein the figures include the following reference numerals:

1. an expansion body; 10. a deformable outer layer; 20. a deformable inner layer; 30. a swelling agent; 40. initiating a crack; 41. and (5) new cracks.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

As shown in fig. 1 and 2, in the present embodiment, the inflation body includes: deformable outer layer 10, deformable inner layer 20, and expanding agent 30. Deformable inner layer 20 is disposed inside deformable outer layer 10, and the inside of deformable inner layer 20 has a receiving cavity; the expansion agent 30 is disposed in the receiving cavity.

By applying the technical scheme of the embodiment, the expansion body 1 comprises the deformable inner layer 20 and the deformable outer layer 10, a containing cavity is formed inside the deformable inner layer 20, the containing cavity is filled with the expanding agent 30, and when the expanding agent 30 begins to expand, the volume of the expansion body 1 can be increased. When the expansion body 1 is placed in a crack, the expansion body 1 increases in volume to prop the crack, so that the crack is further enlarged. Therefore, the technical scheme of the embodiment effectively solves the problem of poor hydraulic fracturing effect in the related art.

As shown in fig. 1 and 2, in the present embodiment, the deformable outer layer 10 is made of rubber, and the deformable inner layer 20 is made of polyester film. The polyester film has good heat shrinkability and good heat resistance, can prevent the expanding agent 30 of the deformable inner layer 20 from contacting with rubber, and the rubber has good tensile property, and has a large friction coefficient and is not easy to slide. And the material has good sealing performance, and when the mixture of the expanding agent 30 and water is put into the material, the material can be isolated from the outside, so that other liquid is prevented from entering the expansion body 1 and the expansion effect is prevented from being influenced.

In this example, the main components of the swelling agent are calcium oxide and a catalyst. Under the action of the catalyst, the calcium oxide can expand, so that the volume is increased. And the reaction period of the expanding agent is controllable, so that the operator can predict the cracking condition of the crack.

In this embodiment, the expansion body 1 further includes water disposed in the accommodating cavity, and the mass ratio of the expansion agent to the water is 11: 2. the above proportions enable the expansion effect of the expansion body 1 to be optimised, although a proportion similar to the above proportions may also enable the expansion body 1 to expand, for example 4: 1,5: 1, etc.

As shown in fig. 1 and 2, in the present embodiment, the expansion body 1 is a deformable sphere. Usually, when the expansion body 1 is used, a large number of expansion bodies 1 are in mutual contact, and the deformable sphere can reduce gaps among a large number of expansion bodies 1, so that the expansion propping effect is better.

In the embodiment not shown in the figures, the expansion body can be arranged in other shapes, such as a cone, a cuboid and the like, and the expansion body can be arranged according to the requirements of actual conditions on site, so that the effect of expansion propping can be optimized.

According to another aspect of the present embodiment, there is provided a conglomerate reservoir modification method, as shown in fig. 4, using the expansion body 1 described above, comprising the steps of:

step S10: forming an initial fracture 40 within the formation and injecting proppant;

step S20: manufacturing an expansion body 1;

step S30: mixing a plurality of expansion bodies 1 into a first fracturing fluid and injecting the mixture into an initial fracture 40;

step S40: the interior of the expansion body 1 is subjected to hydration reaction for a predetermined period of time, and expands to prop the initial crack 40, thereby forming a new crack 41.

By injecting the expansion body 1 into the fracture with the first fracturing fluid through the above steps, the expansion body 1 can be gathered in the fracture, and after a predetermined time, the expansion body starts to expand, starts propping up the initial fracture 40, and forms a new fracture 41. When the hydraulic fracturing effect is poor, the method can be used for propping open the fracture, so that the expansion body 1 can be conveniently conveyed in the initial fracture 40. At the same time, the expansion body 1 is more easily transported in the initial crack 40, since the expansion body 1 is deformable.

As shown in fig. 3, in the present embodiment, mainly for conglomerate reservoir fractures, a conglomerate reservoir is first extracted by hydraulic fracturing; when the hydraulic fracture meets large gravel and the crack stopping phenomenon occurs or the fracturing effect is not ideal, the propping agent is injected, and then the expansion agent 30 is used for fracture end fracturing. Wherein the expanding agent 30 is prepared on the ground and further filled into the accommodating cavity to complete the manufacture of the expansion body 1. As the expansion body 1 is injected into the formation and gathers at the tip of the initial fracture 40 by the first fracturing fluid, the volume of the expansion body 1 is increased continuously as the expanding agent 30 reacts, and a plurality of expansion bodies 1 interact with each other to generate a larger expansion force to act on the fracture wall of the initial fracture 40, so that the fracture is promoted to penetrate through gravel to form a new fracture 41. By alternately performing hydraulic fracturing and expansion body 1 fracturing, a conglomerate reservoir is effectively improved, and the oil gas recovery ratio is improved. And the expanding agent 30 generates pressure by itself, so that additional pressure is not required to be continuously provided on site, and the production cost can be reduced.

In this embodiment (not shown in the figure), in step S20, the step of manufacturing the expansion body includes the steps of: manufacturing a deformable inner layer 20 by using a polyester film and forming an accommodating cavity, wherein the deformable inner layer is provided with an injection port; mixing the expanding agent 30 with water and injecting the mixture into the accommodating cavity through the injection port; the deformable inner layer 20 is placed into the heated liquid rubber and the liquid rubber is formed into the deformable outer layer 10 that surrounds the deformable inner layer 20. The deformable inner layer 20 can effectively contain a mixture of the expanding agent 30 and water, the mixture is not easy to spill, the polyester film has good heat resistance, the expanding agent 30 can be prevented from being in direct contact with heated liquid rubber, and the condition that the expanding agent 30 fails or the reaction speed is accelerated is avoided. By placing deformable inner layer 20 directly into the liquid rubber, the liquid rubber does not enter deformable inner layer 20 into contact with swelling agent 30 because of the small openings in deformable inner layer 20.

Of course, in other embodiments, a structure such as a clip may be provided to seal the injection port of the mylar film, and the injection port may be closed by the clip.

In the present embodiment, in step S10, the initial fracture 40 is formed in a fractured manner by the second fracturing fluid, and a proppant is mixed into the second fracturing fluid. The proppant can effectively prop the fracture and prevent the fracture from closing.

In the present embodiment (not shown in the figure), in step S30, the volume ratio of the expansion bodies 1 to the first fracturing fluid is 1:9, and the injection is stopped after the plurality of expansion bodies 1 are gathered at the tip of the initial fracture 40. When the first fracturing fluid is injected, it is injected at a greater injection rate, facilitating the flow of the expansion body 1 through the initial fracture 40 to the tip of the initial fracture 40. The judgment basis for stopping the injection is that the volume of the second fracturing fluid is the same as that of the first fracturing fluid, and when the second fracturing fluid is injected for 500m³Then the first fracturing fluid is injected into the well for 500m³The volume of the expansion body 1 in the first fracturing fluid is 45m³. The volume ratio of the expansion body 1 to the first fracturing fluid is, of course, 1:7 to 1: 12, the expansion body 1 can support the crack.

In the present embodiment, the predetermined time is between 6 hours and 15 hours. The predetermined time may allow the operator a preparation time with which the expansion body 1 may be made and the first fracturing fluid injected into the fracture. When the swelling agent and water are subjected to hydration reaction, the swelling bodies 1 are subjected to volume expansion, the swelling force between every two swelling bodies 1 is increased continuously, and the multiple swelling bodies 1 can be aggregated into a whole due to large friction force between the multiple swelling bodies 1, so that the resultant swelling force is generated conveniently, and therefore, the resultant swelling force acting on the crack wall at the front end of the initial crack 40 is increased continuously, and the initial crack is further promoted to expand forwards slowly and further penetrate through gravel.

As shown in fig. 3, in the present embodiment, portions of the plurality of expansion bodies 1 abut the fracture walls of the initial fracture 40. The butt can make the contact of inflation body 1 and crack wall inseparabler, and then makes the inflation body better that props up the effect of top for new crack 41 is bigger, in order to satisfy the demand.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.