阅读说明：本技术 一种嵌套式储气井的制作方法 (Manufacturing method of nested gas storage well ) 是由 任毅 王晋 郑凯 范高廷 鲁宁 郇冬 何江 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种嵌套式储气井的制作方法,包括步骤一：在现有的储气井中安装内井筒,外井筒的井口焊接有第一法兰,使内井筒的井口伸出外井筒；步骤二：在内井筒的井口焊接第二法兰,第二法兰位于第一法兰上方,通过螺栓将第一法兰与第二法兰固定为一体；步骤三：在第二法兰上表面接井盖。本申请中将内井筒的井口伸出外井筒,在内井筒的井口焊接了第二法兰增加了第二法兰,并将第二法兰与第一法兰通过螺栓紧固为一体,即将外井筒与内井筒通过井口的法兰连接为整体。这样设计,即使内井筒在长时间内循环充气和放气、承受交变内压载荷的过程中,发生形变伸长和缩短,但是上部的两个法兰始终连为一体,大大提高了结构稳定性和安全性能。(The invention discloses a manufacturing method of a nested gas storage well, which comprises the following steps: an inner shaft is installed in an existing gas storage well, and a first flange is welded at the wellhead of an outer shaft, so that the wellhead of the inner shaft extends out of the outer shaft; step two: welding a second flange at the mouth of the inner shaft, wherein the second flange is positioned above the first flange, and fixing the first flange and the second flange into a whole through bolts; step three: and the upper surface of the second flange is connected with a well cover. Stretch out outer pit shaft with the well head of interior pit shaft in this application, the well head of interior pit shaft has welded the second flange and has increased the second flange to pass through the bolt fastening with second flange and first flange as an organic whole, be about to outer pit shaft and the flange joint of interior pit shaft through the well head as a whole. By the design, even if the inner shaft is subjected to deformation elongation and shortening in the process of circularly inflating and deflating for a long time and bearing alternating internal pressure load, the two flanges on the upper part are connected into a whole all the time, and the structural stability and the safety performance are greatly improved.)

1. A manufacturing method of a nested gas storage well is characterized by comprising the following steps:

the method comprises the following steps: installing an inner shaft in the existing gas storage well, wherein the shaft of the existing gas storage well is marked as an outer shaft, and a first flange is welded at the wellhead of the outer shaft, so that the wellhead of the inner shaft extends out of the outer shaft;

step two: welding a second flange at the mouth of the inner shaft, wherein the second flange is positioned above the first flange, and then fixing the first flange and the second flange into a whole through bolts, and the second flange and the first flange are both concave-convex flanges;

step three: and the upper surface of the second flange is provided with a well cover.

2. The method of making a nested gas storage well of claim 1 wherein a support frame is positioned between the first and second flanges.

3. The method of making a nested gas storage well of claim 2 wherein the support frame is a grommet;

after the first step, the backing ring is placed on the first flange, the upper end of the inner well cylinder is sleeved, then the second flange is placed on the backing ring, and the second flange and the inner well cylinder are welded into a whole.

4. The manufacturing method of the nested gas storage well as claimed in claim 3, wherein the diameter of the second flange is the same as that of the first flange, the well cover is a third flange, the diameter of the third flange is smaller than that of the second flange, and the second flange is provided with two circles of threaded holes, including an outer circle threaded hole and an inner circle threaded hole; the first flange is provided with a plurality of first threaded holes, and the third flange is provided with a plurality of third threaded holes; the first threaded hole corresponds to the outer ring threaded hole, the third threaded hole corresponds to the inner ring threaded hole, the second flange and the first flange are fixed through a first stud screwed into the first threaded hole and the outer ring threaded hole, and the second flange and the well lid are fixed through a third stud screwed into the third threaded hole and the inner ring threaded hole.

5. The manufacturing method of the nested gas storage well according to claim 3, wherein the well lid is a third flange, the first flange, the second flange and the third flange have the same diameter, a circle of second threaded holes are formed in corresponding positions of the first flange, the second flange and the third flange, and the first flange, the second flange and the third flange are fixed through second studs screwed into the second threaded holes;

the second stud is matched with the three nuts and is sequentially marked as a first nut, a second nut and a third nut from bottom to top; the third nut abuts against the upper surface of the third flange, the second nut abuts against the lower surface of the second flange, and the first nut abuts against the lower surface of the first flange.

6. The method of claim 5, wherein the second stud is engaged with the three nuts, the second nut is then engaged with the third nut, the second nut and the third nut are tightened with a torque wrench to lock the second flange and the third flange together, and the first nut is finally engaged with the second nut.

7. The method of making a nested gas storage well of any one of claims 1 to 6, wherein after step one, the gap between the inner and outer well bores is filled with a sealing material.

8. The method of making a nested gas storage well of claim 7 wherein the sealing material fills only the upper gap adjacent the first flange.

9. The method of making a nested gas storage well of claim 7 wherein the sealing material fills the gap between the inner and outer well bores.

10. The method of making a nested gas storage well of claim 7 wherein the sealing material is a foam cement or concrete.

Technical Field

The invention belongs to the technical field of gas storage wells, and particularly relates to a manufacturing method of a nested gas storage well.

Background

At present, CNG gas stations mainly provide gas sources for urban public transport and are built in densely populated cities. The gas storage well is a tubular facility which is vertically buried underground, fully filled and sealed by cement slurry between a shaft and a well wall and used for storing compressed gas, belongs to the category of fixed pressure containers and the variety of high-pressure containers, and has the depth of more than 100 meters. The gas storage well consists of a shaft, a wellhead device and a shaft bottom device. The gas storage well works in a cyclic inflation and deflation process, and mainly bears alternating internal pressure load, the pressure range is generally 10-25 MPa, the pressure fluctuation is more than 20%, and the total number of designed pressure cycles is generally 25000 times. The nominal pressure of the gas storage well is generally 25MPa (gauge pressure), and the nominal volume of the gas storage well is 1-10 m³And the inner diameter of the well bore is 177.8mm and 244.48 mm.

The pit shaft includes a plurality of pit shaft units, and the both ends of pit shaft unit all are provided with the external screw thread, and the connecting portion cover of two adjacent pit shaft units is equipped with connecting sleeve, and connecting sleeve's inner wall is provided with the internal thread, and connecting sleeve and pit shaft unit threaded connection scribble sealed fat in joint seam department. However, the gas storage well bears alternating internal pressure load in the process of circulating inflation and deflation, works for a long time, and the underground environment is severe, so that the sealing grease is dried and reduced, cracks and even falls off, and the joint of two adjacent shaft units leaks. Because the gas storage well is buried underground, the leakage part is not easy to repair, and the repair cost is too high, so in order to avoid abandoning the leaked gas storage well, most of the existing methods are to install an inner well bore with a smaller diameter in the gas storage well to form a nested gas storage well.

In the existing nested gas storage well, in order to fix the inner well shaft, concrete is filled in a gap between the inner well shaft and the outer well shaft, and the inner well shaft and the outer well shaft are not connected together through other components. But interior pit shaft is at the in-process of long-time inner loop inflation and gassing, bearing the alternating internal pressure load, and interior pit shaft can circulate and take place deformation extension and shorten, then interior pit shaft takes place to break away from with the concrete of packing, leads to interior pit shaft to take place to rock, can't link firmly as an organic whole with outer pit shaft, has the potential safety hazard, consequently needs design a better nested formula gas storage well.

Disclosure of Invention

The invention aims to provide a manufacturing method of a nested gas storage well, and the technical problems that concrete is filled between an inner shaft and an outer shaft of the nested gas storage well in the prior art, the inner shaft is separated from the filled concrete in the process of long-time cyclic inflation and deflation and bearing alternating internal pressure load, the inner shaft shakes and cannot be fixedly connected with the outer shaft into a whole, and potential safety hazards exist are solved.

In order to solve the problems, the invention is realized by the following technical scheme:

a manufacturing method of a nested gas storage well comprises the following steps:

the method comprises the following steps: installing an inner shaft in the existing gas storage well, wherein the shaft of the existing gas storage well is marked as an outer shaft, and a first flange is welded at the wellhead of the outer shaft, so that the wellhead of the inner shaft extends out of the outer shaft;

step two: welding a second flange at the mouth of the inner shaft, wherein the second flange is positioned above the first flange, and then fixing the first flange and the second flange into a whole through bolts, and the second flange and the first flange are both concave-convex flanges;

step three: and the upper surface of the second flange is provided with a well cover.

Compared with the prior art, the well head that will interior pit shaft in this application stretches out outer pit shaft, and the well head that includes the pit shaft has welded the second flange and has increased the second flange to pass through the bolt fastening with second flange and first flange as an organic whole, be about to outer pit shaft and the flange joint that interior pit shaft passes through the well head as a whole. By the design, even if the inner shaft circularly inflates and deflates for a long time and bears the alternating internal pressure load, the inner shaft circularly deforms, extends and shortens, the two flanges on the upper part are always connected into a whole, and the structural stability and the safety performance are greatly improved.

In a further improvement, a support frame is arranged between the first flange and the second flange; through setting up the support frame, leave installation space for the double-screw bolt, the operation of being convenient for.

In a further improvement, the support frame is a backing ring; after the first step, the backing ring is placed on the first flange, the upper end of the inner well cylinder is sleeved, the second flange is placed on the backing ring, and the second flange and the inner well cylinder are welded into a whole, so that the assembly is convenient.

The diameter of the second flange is the same as that of the first flange, the well cover is a third flange, the diameter of the third flange is smaller than that of the second flange, and the second flange is provided with two circles of threaded holes which comprise an outer circle threaded hole and an inner circle threaded hole; the first flange is provided with a plurality of first threaded holes, and the third flange is provided with a plurality of third threaded holes; the first threaded hole corresponds to the outer ring threaded hole, the third threaded hole corresponds to the inner ring threaded hole, the second flange and the first flange are fixed through a first stud screwed into the first threaded hole and the outer ring threaded hole, and the second flange and the well lid are fixed through a third stud screwed into the third threaded hole and the inner ring threaded hole.

The well lid is further improved to be a third flange, the diameters of the first flange, the second flange and the third flange are the same, a circle of second threaded holes are formed in corresponding positions of the first flange, the second flange and the third flange, and the first flange, the second flange and the third flange are fixed through second studs screwed into the second threaded holes;

the second stud is matched with the three nuts and is sequentially marked as a first nut, a second nut and a third nut from bottom to top; the third nut abuts against the upper surface of the third flange, the second nut abuts against the lower surface of the second flange, and the first nut abuts against the lower surface of the first flange.

In a further improvement, when the second stud is matched with the three nuts, the second nut is firstly installed, then the third nut is installed, the second nut and the third nut are screwed up by a torque wrench, so that the second flange and the third flange are locked, and finally the first nut is installed. The first nut installation torque may be less than the torques of the second and third nuts.

In a further refinement, after the first step, a sealing material is filled in the gap between the inner wellbore and the outer wellbore. Rain water, impurities and the like are prevented from entering the gap between the inner shaft and the outer shaft.

In a further development, the sealing material only fills the upper gap close to the first flange.

In a further refinement, the sealing material fills a gap between the inner wellbore and the outer wellbore.

In a further improvement, the sealing material is foam rubber or concrete.

Compared with the prior art, the invention has the beneficial effects that:

stretch out outer pit shaft with the well head of interior pit shaft in this application, the well head of interior pit shaft has welded the second flange and has increased the second flange to pass through the bolt fastening with second flange and first flange as an organic whole, be about to outer pit shaft and the flange joint of interior pit shaft through the well head as a whole. By the design, even if the inner shaft circularly inflates and deflates for a long time and bears the alternating internal pressure load, the inner shaft circularly deforms, extends and shortens, the two flanges on the upper part are always connected into a whole, and the structural stability and the safety performance are greatly improved.

Drawings

FIG. 1 is a flow chart of a method of making a nested gas storage well;

FIG. 2 is a cross-sectional view of a nested gas reservoir along an axis according to one embodiment;

FIG. 3 is a top view of the nested gas storage well of FIG. 2;

FIG. 4 is a cross-sectional view of a nested gas well taken along the axis of the gas well of the second embodiment;

FIG. 5 is a top view of the nested gas storage well of FIG. 4.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

The first embodiment is as follows:

as shown in fig. 1-3, a method for manufacturing a nested gas storage well comprises the following steps:

s1: an inner shaft 2 is installed in an existing gas storage well, the shaft of the existing gas storage well is marked as an outer shaft 1, and a first flange 3 is welded at the mouth of the outer shaft, so that the mouth of the inner shaft 2 extends out of the outer shaft 1;

s2: filling a sealing material in a gap between the inner shaft 2 and the outer shaft 1; the sealing material 7 only fills the upper gap near the first flange 3. The sealing material is foaming glue.

S3: placing a stainless steel backing ring 6 on the first flange and sleeving the upper end of the inner shaft 2;

s4: placing a second flange 4 on a backing ring 6, welding the second flange and the inner well bore into a whole, positioning the second flange 4 above the first flange 3, fixing the first flange and the second flange into a whole through bolts, and enabling the second flange 4 and the first flange 3 to be both concave-convex flanges;

s5: with well lid 5 through installing at 4 upper surfaces of second flange, the diameter of well lid 5 is less than the diameter of second flange.

In this embodiment, the second flange is the same as the first flange model, is 9 cun gas storage well flange. The well lid 5 is a third flange, the diameter of the third flange is smaller than that of the second flange, and the second flange 5 is provided with two circles of threaded holes which comprise an outer circle threaded hole 41 and an inner circle threaded hole 42; the first flange is provided with a plurality of first threaded holes, and the third flange is provided with a plurality of third threaded holes; the first threaded hole corresponds to the outer ring threaded hole, the third threaded hole corresponds to the inner ring threaded hole, the second flange is fixed to the first flange through a first stud 11 screwed into the first threaded hole and the outer ring threaded hole, and the second flange is fixed to the well lid through a third stud 13 screwed into the third threaded hole and the inner ring threaded hole, as shown in fig. 3.

In this embodiment, the first stud and the third stud are made of 35 crmoii-grade forgings, and the nut is made of 30 CrMo. The backing ring is a 35 CrMoIII-grade forged piece, the width of the backing ring is not less than 20mm, the height of the backing ring is not less than 2.5 nuts, and the operation is convenient.

Compared with the prior art, the well head that will interior pit shaft in this application stretches out outer pit shaft, and the well head that includes the pit shaft has welded the second flange and has increased the second flange to pass through the bolt fastening with second flange and first flange as an organic whole, be about to outer pit shaft and the flange joint that interior pit shaft passes through the well head as a whole. By the design, even if the inner shaft circularly inflates and deflates for a long time and bears the alternating internal pressure load, the inner shaft circularly deforms, extends and shortens, the two flanges on the upper part are always connected into a whole, and the structural stability and the safety performance are greatly improved.

In other embodiments, the support frame may be a plurality of support blocks.

In other embodiments, the sealing material 7 fills the gap between the inner and outer wellbores.

In other embodiments, the sealing material may be concrete or the like, so long as it is capable of filling and sealing the gap between the inner and outer wellbores.

Example two:

as shown in fig. 4 and 5, the well lid 5 is a third flange, and the diameters of the first flange 3, the second flange 4 and the third flange are the same, and are all 9 inches flanges of the gas storage well. Corresponding positions on the first flange, the second flange and the third flange are provided with a circle of second threaded holes 51, and the first flange, the second flange and the third flange are fixed through second studs 8 screwed into the second threaded holes.

In this embodiment, the second stud is matched with three nuts, and is sequentially marked as a first nut 21, a second nut 22 and a third nut 23 from bottom to top; the third nut abuts against the upper surface of the third flange, the second nut abuts against the lower surface of the second flange, and the first nut abuts against the lower surface of the first flange. Be convenient for fasten second flange and well lid 5 through setting up three nut.

When the second stud 8 is matched with the three nuts, the second nut 22 is installed, then the third nut 23 is installed, the second nut and the third nut are screwed by a torque wrench to lock the second flange 4 and the third flange, and finally the first nut 21 is installed. The first nut installation torque may be less than the torques of the second and third nuts.

In this embodiment, the second stud is made of a 35 CrMoIII-grade forging, and the nut is made of a 30CrMo material.

The other parts are the same as in the first embodiment.

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; 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.