阅读说明：本技术 盐穴地下储库建库方法及装置 (Salt cavern underground storage warehouse building method and device ) 是由 庄晓谦 袁光杰 夏焱 李国韬 路立君 金根泰 杨恒林 班凡生 李景翠 付盼 杨松 于 2019-11-25 设计创作，主要内容包括：本发明实施例提供了一种盐穴地下储库建库方法及装置,其中,该方法包括：在一个井场内设置多口井；将每两口井的井底连通,连通的两口井中一口井用于注水,另一口井用于排卤,在连通的两口井之间形成盐腔,在井场的盐层内得到多个盐腔,其中,盐腔作为存储空间,每个盐腔对应的两口井还用于注采。该方案可以增大单个地下盐腔的有效体积,在相同的盐层厚度条件下,有利于提高盐岩资源的利用率。(The embodiment of the invention provides a method and a device for building a salt cavern underground reservoir, wherein the method comprises the following steps: arranging a plurality of wells in a well site; the bottom of each two wells are communicated, one of the two communicated wells is used for water injection, the other well is used for brine discharge, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in a salt layer of a well site, the salt cavities are used as storage spaces, and the two wells corresponding to each salt cavity are also used for injection and production. The scheme can increase the effective volume of a single underground salt cavity, and is favorable for improving the utilization rate of salt rock resources under the condition of the same salt layer thickness.)

1. A method for building a reservoir in a salt cavern underground reservoir is characterized by comprising the following steps:

arranging a plurality of wells in a well site;

the bottom of each two wells are communicated, one of the two communicated wells is used for water injection, the other well is used for brine discharge, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in a salt layer of a well site, the salt cavities are used as storage spaces, and the two wells corresponding to each salt cavity are also used for injection and production.

2. The method for constructing a salt cavern underground storage library according to claim 1, wherein a salt cavity formed between two wells of the multiple wells is used as a central salt cavity, and one salt cavity is formed between every two wells of the other wells of the multiple wells to obtain a plurality of salt cavities distributed in the surrounding space of the central salt cavity, wherein the two wells corresponding to the central salt cavity comprise a vertical well or a directional injection and production well with a displacement smaller than a preset value, and the other wells of the multiple wells are directional injection and production wells.

3. The method of claim 1, wherein the two wells of each salt cavity have a bottom-hole horizontal distance of 30-40 m.

4. The method for constructing a salt cavern underground reservoir as claimed in any one of claims 1 to 3, wherein the distance between the wellheads of two adjacent wells in the plurality of wells is a preset distance which meets construction safety conditions.

5. The method of warehousing a salt cavern underground reservoir of claim 4,

the preset distance is 10-15 meters.

6. The utility model provides a device is built to salt cavern underground storage storehouse which characterized in that includes:

drilling equipment for setting a plurality of wells in a wellsite;

and the injection and production equipment is used for communicating the bottoms of every two wells, one of the two communicated wells is used for injecting water, the other well is used for discharging brine, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in a salt layer of a well site, the salt cavities are used as storage spaces, and the two wells corresponding to each salt cavity are also used for injection and production.

7. The device for building a salt cavern underground storage according to claim 6, wherein a salt cavity formed between two wells of the plurality of wells is used as a central salt cavity, one salt cavity is formed between every two wells of the other wells of the plurality of wells, and a plurality of salt cavities are obtained and distributed in the surrounding space of the central salt cavity, wherein the two wells corresponding to the central salt cavity comprise a straight well or a directional injection and production well with a displacement smaller than a preset value, and the other wells of the plurality of wells are directional injection and production wells.

8. The device for constructing the salt cavern underground storage as claimed in claim 6, wherein the bottom-hole horizontal distance of the two wells corresponding to each salt cavity is 30-40 m.

9. The device for building the salt cavern underground storage according to any one of claims 6 to 8, wherein the distance between the wellheads of two adjacent wells in the plurality of wells is a preset distance which meets construction safety conditions.

10. The cavern underground storage warehousing device of claim 9, wherein the predetermined distance is 10 to 15 meters.

Technical Field

The invention relates to the technical field of natural gas, in particular to a method and a device for building a salt cavern underground reservoir.

Background

The salt cavern underground storage is one of the main types of storage, and utilizes a thicker salt layer or a salt dome underground, and artificially dissolves water in the salt layer or the salt dome to form a cavern storage space for storing natural gas or other storage media. The storage has the advantages of high safety, large capacity, high injection-production speed and low operation cost, and has been well applied to developed countries in western parts such as America, France, Germany and Russia.

The gold jar salt cavern gas storage is the first salt cavern underground gas storage in China, the time for building the storage is over 10 years, the drilling mode of the salt cavern injection and production well at the early stage is mostly a vertical well, and the cavity type is a single well and a single cavity. Due to the limitation of the thickness of a salt layer, the size of a shaft, a cavity building mode and the like, the effective volume of a salt cavity is generally about 20-25 ten thousand square, and is obviously smaller than that of a foreign salt cavity, so that salt rock resources are difficult to fully utilize, the reservoir building capacity is slower, and the reservoir capacity is smaller.

Disclosure of Invention

The embodiment of the invention provides a method for building a salt cavern underground reservoir, which aims to solve the technical problem of small reservoir capacity in the prior art. The method comprises the following steps:

arranging a plurality of wells in a well site;

the bottom of each two wells are communicated, one of the two communicated wells is used for water injection, the other well is used for brine discharge, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in a salt layer of a well site, the salt cavities are used as storage spaces, and the two wells corresponding to each salt cavity are also used for injection and production.

The embodiment of the invention also provides a device for building the salt cavern underground storage, which aims to solve the technical problem of small storage capacity in the building of the salt cavern underground storage in the prior art. The device includes:

drilling equipment for setting a plurality of wells in a wellsite;

and the injection and production equipment is used for communicating the bottoms of every two wells, one of the two communicated wells is used for injecting water, the other well is used for discharging brine, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in a salt layer of a well site, the salt cavities are used as storage spaces, and the two wells corresponding to each salt cavity are also used for injection and production.

In the embodiment of the invention, a plurality of wells are arranged in a well site, the bottoms of every two wells are communicated, one of the two communicated wells is used for injecting water, the other well is used for discharging brine, a solution cavity is formed gradually, a salt cavity is formed between the two communicated wells, namely, the underground salt cavity is built in a double-well single-cavity mode, and then a plurality of salt cavities are obtained in a salt layer of the well site, so that the arrangement of the plurality of wells in one well site is realized, a plurality of salt cavities are formed, the factory building of a warehouse is facilitated, and the salt cavity is formed between the two communicated wells, so that the underground salt cavity is built in a double-well single-cavity mode, compared with the underground salt cavity built in a single-well single-cavity mode in the prior art, the underground salt cavity built in the double-well single-cavity mode can increase the effective volume of a single salt cavity, and further increase the storage capacity of a salt cavern underground storage, under the same salt layer thickness condition, is favorable for improving the utilization rate of the salt rock resources.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a flow chart of a method for building a salt cavern underground reservoir according to an embodiment of the invention;

FIG. 2 is a schematic plan view of a factory-built well according to an embodiment of the present invention;

FIG. 3 is a schematic illustration of a downhole location within a well site provided by an embodiment of the present invention;

FIG. 4 is a schematic illustration of a distribution of salt cavity locations within a wellsite, according to an embodiment of the present disclosure;

FIG. 5 is a 3D schematic diagram of a salt cavern reservoir dual-well cavity-building-one vertical well and a salt cavern reservoir directional well-building manner provided by the embodiment of the invention;

FIG. 6 is a 3D schematic diagram of a salt cavern reservoir dual-well cavity-building dual-directional well-building method provided by an embodiment of the invention;

FIG. 7 is a 3D schematic diagram of a salt cavern reservoir dual-well cavity-building vertical well and inclined well building manner provided by the embodiment of the invention;

fig. 8 is a schematic structural diagram of a device for building a salt cavern underground storage provided by the embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.

In an embodiment of the present invention, there is provided a method for constructing a salt cavern underground reservoir, as shown in fig. 1, the method including:

step 102: arranging a plurality of wells in a well site;

step 104: the bottom of every two wells is communicated, one of the two communicated wells is used for water injection, the other well is used for discharging brine, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in the salt layer of the well site, the salt cavities serve as storage spaces, and the two wells corresponding to each salt cavity are further used for injection production (namely, the two wells corresponding to each salt cavity can be used for collecting natural gas or other storage media stored in the salt cavity, and in a specific injection production process, one of the two wells can be used for injection production or two wells can be used for simultaneous injection production according to actual requirements).

As can be seen from the flow shown in fig. 1, in the embodiment of the present invention, multiple wells are disposed in one well site, and the bottoms of each two wells are connected, one of the two wells is used for water injection, the other well is used for discharging brine, so as to gradually form a solution cavity, so as to form a salt cavity between the two connected wells, i.e., each salt cavity is formed by circulating brine injection and discharge after the two wells are connected, thereby realizing the construction of an underground salt cavity based on a double-well single-cavity manner, further obtaining multiple salt cavities in the salt layer of the well site, so as to realize the arrangement of multiple wells in one well site, forming multiple salt cavities, which is beneficial for the construction of a factory chemical reservoir, and forming a salt cavity between the two connected wells, realizing the construction of an underground salt cavity based on a double-well single-cavity manner, compared with the underground salt cavity constructed based on a single-well single-cavity manner in the prior art, the effective volume of a single salt cavity can be increased by the underground salt cavity constructed based on a double-well single-cavity manner in, under the condition of the same thickness of the salt layer, the utilization rate of the salt rock resource is improved.

In particular, the well site is a drilling area having a desired salt layer thickness for a salt cavern reservoir.

In the embodiment, a salt cavity formed between two wells of the multiple wells is used as a central salt cavity, a salt cavity is formed between every two wells of other wells of the multiple wells to obtain multiple salt cavities, the multiple salt cavities are distributed in the surrounding space of the central salt cavity, the distance required by the safe operation is kept without mutual influence between adjacent salt cavities, the two wells corresponding to the central salt cavity comprise vertical wells or directional injection and production wells with displacement smaller than a preset value, and the other wells of the multiple wells are directional injection and production wells.

For example, as shown in fig. 2 to 4, 0 indicates the well site, 1 to 5 indicates the location of the salt cavity, 1 to 5 indicates the track of two wells corresponding to one salt cavity, and as can be seen from fig. 1, the salt cavity 1 is formed by two vertical wells, the salt cavities 2 to 5 are formed by two directional injection and production wells, respectively, as can be seen from fig. 2 to 4 (the ellipses 1 to 5 filled with lines in fig. 4 indicate the salt cavities), the salt cavity 1 formed by the two vertical wells is located at the center as the central salt cavity, and the other salt cavities 2 to 5 formed by the directional injection and production wells are distributed in the space around the salt cavity 1, for example, the salt cavities 2 to 5 may be distributed at different depths and different horizontal distances in the same salt layer in the space around the salt cavity 1.

In specific implementation, the plurality of salt cavities can also be uniformly distributed in the surrounding space of the central salt cavity, as shown in fig. 3 and 4.

In a specific implementation, the salt cavities may be shaped as cavities with cross sections that are approximately elliptical.

In specific implementation, the directional injection and production well can be an inclined well with different well inclination angles and the like. The directional injection and production well is a salt cavern gas storage well type of a salt cavern shaft constructed by drilling a directional well in order to improve the utilization rate of rock salt resources.

In the specific implementation, in the process of building the underground salt cavities by adopting a double-well single-cavity type, the horizontal distance between the bottoms of the two wells corresponding to each salt cavity can be 30-40 m. Specifically, the bottoms of two wells corresponding to each salt cavity are communicated by a natural corrosion method or a communication tool or a directional horizontal drilling method, water is injected into one well, brine is discharged from the other well, and the salt cavity is formed gradually, so that the effective volume of the salt cavity constructed by the method can be more than 1.5 times that of the salt cavity constructed by a conventional single well and a single cavity.

In specific implementation, in order to further intensively arrange a plurality of wells in a well site, in addition to reasonable arrangement of ground conditions (influence factors such as old wells, topography and landform), in order to ensure that the wells are safe to each other and do not influence construction, the distance between the well mouths of two adjacent wells in the plurality of wells is a preset distance which meets the construction safety conditions, and for example, the preset distance may be 10 to 15 meters. Specifically, in order to achieve the goal of factory-based library building, a plurality of wells are arranged at the same well site, the number of the wells can be 4-10, or any other number of wells suitable for the surface conditions of a new well site or an old well site and the library building requirement. The well is exemplified by 10-hole well arrangement, and the wells can be vertical wells and can also be directional injection and production wells of salt cavern reservoirs.

In specific implementation, in the process of putting the salt cavern reservoir into the double-well chamber construction, the well construction implementation method of the two wells corresponding to each salt cavern may include various situations, for example, as shown in fig. 5, a situation where a well is constructed for a straight well a and a salt cavern reservoir directional injection and production well B, as shown in fig. 6, a situation where a well is constructed for two salt cavern reservoir directional injection and production wells, as shown in fig. 7, a situation where a well is constructed for a straight well a and an inclined well C. The method aims to build a plurality of wells at the same well site or by using old well sites, wherein each two wells form a salt cavity, and the two wells on the same salt cavity are used for completing cavity building and injection-production operation, so that a salt cavern storage group is finally built.

During specific implementation, in the implementation process of the salt cavern underground storage warehouse building method, due to the fact that multiple wells are arranged on the same well site, compared with the mode of a single well and a single cavity in the prior art, the multiple wells in the same well site are concentrated, the advantages of underground engineering, ground construction and later operation are obvious, seamless butt joint of all working procedures is facilitated, factory operation management in later injection and production operation stages is facilitated, operation cost and difficulty are reduced, and safety is improved. The concrete aspects are as follows:

(1) the restriction of landform to well site positions is reduced, land is saved, the construction of single well sites and roads before drilling is reduced, and the well construction period is shortened;

(2) the construction speed is improved, the construction cost is greatly reduced, the maintenance cost of a single well after production is reduced, and unified management is facilitated;

(3) the salt cavern warehouse building factory operation has obvious advantages in underground engineering, ground construction and later operation, is beneficial to seamless butt joint of all procedures and factory operation management in the later injection-production operation stage, reduces operation cost and difficulty, and improves safety. The concrete aspects are as follows:

a plurality of well heads are distributed in the same well field, so that the drilling machine is convenient to move, the possibility is provided for the operations of drilling fluid cyclic utilization, non-landing treatment and the like, and the drilling production is facilitated;

a plurality of wells and a plurality of cavities of the cavity-making ground pipeline are uniformly arranged, so that brine can be conveniently and circularly collected;

multiple salt cavities of the injection and production ground pipeline are uniformly arranged, an injection and production safety control system is coordinately arranged, injection and production operation is optimally managed according to well field distribution, safety is improved, and management difficulty is reduced;

the processes of tubular column adjustment, sonar test, air-tight seal pressure test, injection and production completion and the like are efficiently linked, multiple wells and multiple cavities are coordinately carried out, and the operation cost is reduced.

The double-well cavity-building industrial reservoir building method for the salt cavern reservoir has very important significance for solving the problems of low reservoir building speed and high reservoir building cost under the realistic condition that salt rock resources in China are scarce.

Based on the same inventive concept, the embodiment of the invention also provides a device for building the salt cavern underground storage, which is described in the following embodiment. The principle of solving the problems of the salt cavern underground storage building device is similar to that of the salt cavern underground storage building method, so the implementation of the salt cavern underground storage building device can refer to the implementation of the salt cavern underground storage building method, and repeated parts are not repeated. As used hereinafter, the term "unit" or "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 8 is a block diagram showing a structure of a device for building a cavern underground reservoir according to an embodiment of the present invention, as shown in fig. 8, the device includes:

drilling equipment 802 for setting multiple wells in a wellsite;

and the injection and production equipment 804 is used for communicating the bottoms of every two wells, one of the two communicated wells is used for injecting water, the other well is used for discharging brine, a salt cavity is formed between the two communicated wells, a plurality of salt cavities are obtained in a salt layer of a well site, the salt cavities are used as storage spaces, and the two wells corresponding to each salt cavity are also used for injection and production.

In one embodiment, a salt cavity formed between two wells of the multiple wells is used as a central salt cavity, and a salt cavity is formed between every two wells of the other wells of the multiple wells to obtain a plurality of salt cavities which are distributed in the surrounding space of the central salt cavity, wherein the two wells corresponding to the central salt cavity comprise vertical wells or directional injection and production wells with displacement smaller than a preset value, and the other wells of the multiple wells are directional injection and production wells.

In one embodiment, the bottom hole horizontal distance of the two wells corresponding to each salt cavity is 30-40 meters.

In one embodiment, the distance between the well heads of two adjacent wells in the plurality of wells is a preset distance which meets construction safety conditions.

In one embodiment, the predetermined distance is 10 to 15 meters.

The embodiment of the invention realizes the following technical effects: through setting up the multiple wells in a well site, and with the shaft bottom intercommunication of every two wells, one well in two communicated wells is used for the water injection, another well is used for discharging bittern, form the solution chamber gradually, form the salt chamber between two communicated wells, realized building the secret salt chamber based on the mode of twin-well single chamber, and then obtain a plurality of salt chambers in the salt deposit in well site, make the setting of multiple wells realize in a well site, form a plurality of salt chambers, be favorable to realizing the factory building storehouse, and form the salt chamber between two communicated wells, realized building the secret salt chamber based on the mode of twin-well single chamber, compare with the secret salt chamber based on single-well single chamber mode is built among the prior art, the secret salt chamber that this application was built based on the mode of twin-well single chamber can increase the effective volume of single salt chamber, under the same salt layer thickness condition, be favorable to improving the utilization ratio of salt rock resource.

It will be apparent to those skilled in the art that the modules or steps of the embodiments of the invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, embodiments of the invention are not limited to any specific combination of hardware and software.

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 to the embodiment of the present invention 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.