CN-116838281-B - Double-oil-extraction four-way concentric double-pipe-column christmas tree and layered gas injection method thereof

CN116838281BCN 116838281 BCN116838281 BCN 116838281BCN-116838281-B

Abstract

The invention discloses a double-oil-extraction four-way concentric double-pipe string christmas tree and a layering gas injection method thereof, wherein an inner oil pipe is positioned in an outer oil pipe, an annular space is formed between the outer wall of the inner oil pipe and the inner wall of the outer oil pipe, and two ends of the inner oil pipe extend out of two ends of the outer oil pipe; the bottom ends of the inner oil pipe and the outer oil pipe are connected with a shaft through two permanent packers, the inner oil pipe and the outer oil pipe are connected with the two permanent packers in a sealing mode through metal return pipe columns, the inner oil pipe hanger and the outer oil pipe hanger are respectively arranged at the tops of the inner oil pipe and the outer oil pipe, the christmas tree is connected with the top of the inner oil pipe hanger, the upper oil extraction four-way is respectively connected with the bottom of the inner oil pipe hanger and the top of the outer oil pipe hanger, and the lower oil extraction four-way is connected with the bottom of the outer oil pipe hanger. The integral sealing performance of the production tree is improved, and long-term stable gas injection is realized.

Inventors

HU CHAO
XIANG WENGANG
ZHAO PENG
ZHU LIANGGEN
WANG CHUNLEI
HE CHUANJIANG
WU YUNCAI
ZHOU ZHONGMING

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260505
Application Date: 20220325

Claims (8)

1. The double-oil-production four-way concentric double-pipe column christmas tree is characterized by comprising a christmas tree (1), an upper oil-production four-way (2), a lower oil-production four-way (3), an inner-layer tubing hanger (4), an outer-layer tubing hanger (5), an inner-layer tubing (6) and an outer-layer tubing (7); The inner layer oil pipe (6) is positioned in the outer layer oil pipe (7), an annular space is formed between the outer wall of the inner layer oil pipe (6) and the inner wall of the outer layer oil pipe (7), an annular space is formed between the outer wall of the outer layer oil pipe (7) and the inner wall of a shaft, two ends of the inner layer oil pipe (6) extend out of two ends of the outer layer oil pipe (7), the bottom ends of the inner layer oil pipe (6) are connected with the shaft through first permanent packers (8), the inner layer oil pipe (6) is in sealing connection with the first permanent packers (8) through first return pipe columns (9), the bottom ends of the outer layer oil pipe (7) are connected with the shaft through second permanent packers (10), the outer layer oil pipe (7) is in sealing connection with the second return pipe columns (11), and metal sealing is adopted between the first return pipe columns (9) and the first permanent packers (8) and the second return pipe columns (11); The oil production system comprises an inner oil pipe hanger (4) and an outer oil pipe hanger (5), wherein the inner oil pipe hanger (4) and the outer oil pipe hanger (5) are respectively arranged at the tops of an inner oil pipe (6) and an outer oil pipe (7), a production tree (1) is connected with the top of the inner oil pipe hanger (4), the production tree (1) is communicated with the inner oil pipe (6) through the inner oil pipe hanger (4), a metal seal is arranged between the tops of the production tree (1) and the inner oil pipe hanger (4), an upper production four-way (2) is respectively connected with the bottom of the inner oil pipe hanger (4) and the top of the outer oil pipe hanger (5), the upper production four-way (2) is communicated with an annular space formed by the outer wall of the inner oil pipe hanger (4) and the top of the outer oil pipe hanger (5), and an annular space formed by the outer wall of the outer oil pipe hanger (7) and the inner wall of the outer oil pipe hanger (5), and the metal seal is arranged between the lower production four-way (3) and the bottom of the outer oil pipe hanger (5); a POP valve is arranged below a first permanent packer (8) of the inner layer oil pipe (6), and a recoverable ball seat is arranged below a second permanent packer (10) of the outer layer oil pipe (7); The feeding end of the inner-layer tubing hanger (4) is set as a female buckle, and the feeding end of the outer-layer tubing hanger (5) is set as a male buckle.
2. The dual oil extraction four-way concentric dual pipe string christmas tree according to claim 1, characterized in that the christmas tree (1), the upper christmas four-way (2) and the lower christmas four-way (3) are connected by means of stud bolts via flanges.
3. The dual oil extraction four-way concentric dual-pipe string christmas tree according to claim 1, characterized in that a steel ring seal is arranged between the upper oil extraction four-way (2) and the lower oil extraction four-way (3).
4. The dual oil recovery four-way concentric dual-string christmas tree according to claim 1, characterized in that the inner layer oil pipe (6) and the outer layer oil pipe (7) are both airtight sealed oil pipes.
5. The dual oil extraction four-way concentric dual-pipe string christmas tree according to claim 1, characterized in that one side of the christmas tree (1), the upper oil extraction four-way (2) and the lower oil extraction four-way (3) is provided with a hydraulic safety valve and a manual valve, the manual valve is on the inner side, the hydraulic safety valve is on the outer side, and the other side of the christmas tree (1), the upper oil extraction four-way (2) and the lower oil extraction four-way (3) is provided with two manual valves.
6. A method for layered gas injection based on the dual oil recovery four-way concentric dual string tree according to any one of claims 1 to 5, comprising the steps of: Step 1, installing a double-oil-extraction four-way concentric double-pipe string christmas tree to finish a well completion procedure; step 2, connecting the test injection pipeline to the christmas tree (1) and the upper production four-way joint (2) respectively, testing the pressure to be qualified, and injecting nitrogen gas to squeeze an annular space formed between the outer wall of the inner layer oil pipe (6) and the inner wall of the outer layer oil pipe (7) and a protective liquid of the inner annulus of the inner layer oil pipe (6) into the stratum And 3, connecting the gas injection pipeline of the production tree (1) and the upper production four-way (2) to the main pipeline, and implementing layered natural gas injection.
7. The method for layering gas injection of the dual-production four-way concentric dual-string christmas tree according to claim 6, wherein the specific process of the well completion procedure is as follows: Step 1.1, installing a lower oil extraction four-way joint (3), and putting a first permanent packer (8) matched with an inner layer oil pipe (6), wherein after ball throwing and pressing, the first permanent packer (8) is set for releasing; Step 1.2, a second permanent packer (10) matched with the lower outer layer oil pipe (7) is put into ball and pressed, and then the second permanent packer (10) of the outer layer oil pipe (7) is set and released; Step 1.3, lifting the outer layer oil pipe (7) to the design tonnage by a second backflow pipe column (11) of the lower outer layer oil pipe (7), and confirming that the second backflow pipe column (11) of the outer layer oil pipe (7) is successfully backflow into a second permanent packer (10) of the outer layer oil pipe (7); Step 1.4, connecting the bottom of the outer layer tubing hanger (5) with the tops of the lower oil extraction four-way joint (3) and the outer layer tubing (7); step 1.5, installing an oil extraction four-way joint (2), and connecting the top of an outer oil pipe hanger (5) with the oil extraction four-way joint (2); step 1.6, lifting the inner layer oil pipe (6) to the design tonnage by the first re-insertion pipe column (9) of the lower inner layer oil pipe (6), and confirming that the first re-insertion pipe column (9) of the inner layer oil pipe (6) is successfully re-inserted into the first permanent packer (8) of the inner layer oil pipe (6); Step 1.7, connecting the bottom of an inner oil pipe hanger (4) with the tops of an inner oil extraction four-way joint and an inner oil pipe (6); and 1.8, installing the Christmas tree (1), and connecting the top of the inner tubing hanger (4) with the Christmas tree (1).
8. The method of claim 7, wherein each step of the completion process is performed before proceeding to the next step.

Description

Double-oil-extraction four-way concentric double-pipe-column christmas tree and layered gas injection method thereof Technical Field The invention belongs to the field of petroleum exploration and development, and relates to a dual-oil-extraction four-way concentric dual-pipe-column christmas tree and a layered gas injection method thereof. Background The circulating gas injection development of the tooth-ha high-pressure condensate gas reservoir in the Tarim oil field has been carried out for 20 years, a mode of injecting dry gas in a general way is always adopted, and as the physical properties of the upper sand body and the lower sand body of the same gas injection layer of the gas injection well are greatly different, the average permeability and the porosity of the upper sand body and the lower sand body are greatly different, the difference of the air suction volumes of the upper sand body and the lower sand body is 9 times according to the analysis of air suction section test data, the pushing interface of the front edge of the dry gas displacement is unbalanced, the gas reservoir storage volume of the gas extraction well is uneven, and the mining contradiction between the high permeable layer and the low permeable layer is outstanding. For better subdivision layer gas injection exploitation, the development of a layered gas injection process research is very important. On the basis, related researches are also carried out all the time, the application of analyse concentric double-tube layered gas injection technology is published in the petrochemical technology of 2016 by Jingfu, the assumption and theoretical calculation of layered gas injection of the dental-cavity gas field are proposed in the natural gas industry of 2016 by Xue Chengwen and the concentric oil tube layered gas injection technology of the dental-cavity high-pressure gas field is published in the natural gas industry of 2016, but no related products and layered gas injection technological methods exist. The existing layered gas injection pipe column is layered by adopting a single pipe and an injection valve. The process is limited by the sizes of the injection valve and the bottom sliding sleeve, the adjustment of the gas injection amount cannot be realized, and once the switch of the injection valve fails, the replacement cannot be performed, the operation needs to be repeated, the reliability is low, and the gas injection cannot be stabilized for a long time. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides the dual-oil-extraction four-way concentric dual-pipe string christmas tree and the layered gas injection method thereof, so that the integral tightness of the christmas tree is improved, and the long-term stable gas injection is realized. In order to achieve the purpose, the invention is realized by adopting the following technical scheme: a dual-oil-production four-way concentric dual-pipe string Christmas tree comprises a Christmas tree, an upper oil-production four-way, a lower oil-production four-way, an inner-layer oil pipe hanger, an outer-layer oil pipe hanger, an inner-layer oil pipe and an outer-layer oil pipe; The inner layer oil pipe is positioned in the outer layer oil pipe, an annular space is formed between the outer wall of the inner layer oil pipe and the inner wall of the outer layer oil pipe, the outer wall of the outer layer oil pipe and the inner wall of a shaft form an annular space, and two ends of the inner layer oil pipe extend out of two ends of the outer layer oil pipe; The inner oil pipe hanger and the outer oil pipe hanger are respectively positioned at the top parts of the inner oil pipe and the outer oil pipe, the christmas tree is connected with the top parts of the inner oil pipe hanger and is communicated with the inner oil pipe through the inner oil pipe hanger, a metal seal is arranged between the christmas tree and the top parts of the inner oil pipe hanger, the upper oil extraction four-way is respectively connected with the bottom parts of the inner oil pipe hanger and the top parts of the outer oil pipe hanger, the upper oil extraction four-way is communicated with an annular space formed between the outer wall of the inner oil pipe and the inner wall of the outer oil pipe through the inner oil pipe hanger and the outer oil pipe hanger, a metal seal is arranged between the lower oil extraction four-way and the bottom parts of the outer oil pipe hanger, the lower oil extraction four-way is connected with the bottom parts of the outer oil pipe hanger and the annular space formed by the outer wall of the outer oil pipe and the inner wall of a shaft. Preferably, a POP valve is arranged below the first permanent packer of the inner layer oil pipe, and a recoverable ball seat is arranged below the second permanent packer of the outer layer oil pipe. Preferably, the feeding end of the inner-layer tubing hanger is set as a female buckle, and the