Progress and enlightenment of Panhe pilot test project of coalbed methane development demonstration project in southern Qinshui basin

(China United Coalbed Methane Co., Ltd. Beijing 1000 1 1)

About the author: Ye Jianping, male, 1962, born in Ninghai, Zhejiang, Ph.D., professor-level senior engineer. Engaged in coalfield geology and exploration, coalbed methane exploration, development, production and scientific research for a long time. Now Zhonglian Coalbed Methane Co., Ltd., address: No.88 A, Anwai Street, Beijing, zip code:11,e-mail address: yejp01@163.com.

Panhe project is a national demonstration project of coalbed methane development officially approved by the National Development and Reform Commission. The drilling and completion of 100 wells and fracturing of 40 wells were completed only one year ahead of schedule, and the surface gathering and transportation project was completed and put into commercial production. The ground gathering and transportation project includes: single well station process flow and 4 sets of valve groups; Gas gathering station with daily pressurization of 80000m3 1 seat; ; One gas supply station with a daily compression of 80000m3；; There is a gas-fired power station with a daily output of 2 175kW, and the total length of gas pipeline is about 4 1km. A set of automatic transmission system and remote monitoring system, as well as the corresponding supporting projects. The production results at the initial stage of drainage and production show that single well has high gas production, high casing pressure and low water production. The average gas production of a single well reaches 2000m3/d, the highest single well production is 7434m3/d, and the average water production is 7m3/d ... This area has good coalbed methane production capacity.

The Panhe project has achieved fruitful results in geological and reservoir research, engineering deployment, well pattern optimization, drilling and completion technology, stimulation and reconstruction technology, drainage and production technology, and gathering and transportation technology of coalbed methane fields. The air drilling technology, nitrogen foam fracturing technology, coal-bed methane field gathering and transportation technology and automatic data acquisition system adopted belong to the leading technologies in China, and many technical achievements are innovative, which has become the dazzling brilliance in the construction process of Panhe project. It closely combines scientific research with engineering projects and becomes a model of combining scientific research with production. The successful construction and commissioning of Panhe project has enabled the company to enter the development stage from the exploration stage of coalbed methane, and has also become a landmark milestone in the development of coalbed methane industry in China.

Keywords: exploration and development of coalbed methane in Qinshui basin Panhe project

Progress and enlightenment of Panhe pilot project of coalbed methane demonstration project in southern Qinshui basin

Ye Jianping Wu Jianguang

(China United Coalbed Methane Co., Ltd., Beijing 1000 1 1)

Abstract: Panhe demonstration project is a national demonstration project of coalbed methane officially approved by the National Development and Reform Commission. In the first stage, it took only one year to complete the drilling and completion of 100 coalbed methane wells, the fracturing operation of 40 wells and the construction of ground gathering and transportation projects, and realized commercial production and natural gas sales. The ground gathering and transportation project includes a single well gas flow system, four sets of valve groups, a gas gathering station with a gas supply capacity of 80,000 cubic meters, a gas supply station with a compression capacity of 80,000 cubic meters, a gas power station with a daily output of 2 175 kW, a coalbed methane pipeline with a total length of 4 1 km, an automatic data transmission system, a remote monitoring system and other corresponding units. The production data of Panhe gas field show that the single well has high coalbed methane production, high annular pressure and low water production. At present, the average daily water production of a single well is about 2000 cubic meters and 7 cubic meters respectively, and the highest daily water production reaches 7434 cubic meters, indicating that this area has good development potential.

The Panhe experimental project has achieved fruitful results in coalbed methane geology and reservoir research, engineering planning, well pattern optimization, drilling and completion technology, stimulation technology, and coalbed methane field gathering and transportation technology. In particular, air drilling technology, nitrogen foam stimulation technology, CBM oilfield acquisition technology and automatic data acquisition technology are in a leading position in China because of their high innovation, which has formed the highlight of Panhe pilot project construction. The combination of research work and engineering construction makes Panhe experimental project a model of combining scientific research with production practice. The successful construction and commercial production of Panhe Project will make the development of coalbed methane in China enter a development stage and become a landmark in the development history of coalbed methane industry in China.

Keywords: coalbed methane; Exploration and development; Qinshui basin; Panhe project; demonstration project

order

The southern Qinshui Basin is the best coalbed methane field discovered in China so far. 1997 Zhonglian CBM Co., Ltd. deployed the first batch of exploration wells in this area, and the first exploration well TL-003 was put into production on 1998, with a single well output of 7000m3/d, which achieved a breakthrough in CBM exploration in China. After that, F Z well group was deployed around it, and by 2002, the production test well group of 15 well was formed, which realized commercial trial production. At the same time, the proven geological reserves of 432× 108m3 coalbed methane in Qinnan coalbed methane field have laid a good foundation for the commercial development of coalbed methane.

On March 12, 2004, after the leadership of the company was changed, the new leadership put forward a clear goal of realizing commercial production of coalbed methane as soon as possible, and decided to deploy pilot test well groups of coalbed methane in panzhuang block in Shanxi and Hancheng block in Shaanxi. At the same time, apply to the National Development and Reform Commission for the establishment of "Qinnan CBM Development and Utilization High-tech Industrialization Demonstration Project". On February 22, 2004, 65438+2004, the National Development and Reform Commission officially approved the establishment of the national demonstration project of coalbed methane development with document [2004]2395. The demonstration project is planned in three stages. In the first stage, 150 wells were deployed, and the annual production capacity in 2006 was 1× 108m3. In the second stage, another 400 ports will be deployed to achieve an annual production capacity of 4× 108m3; In the third phase, another 350 wells will be deployed, bringing the total number to 900 wells. After the third phase is completed, the annual production capacity will reach 7× 108m3, and the coalbed methane production base in Qinshui Basin will be initially established.

Panhe Pilot Project (hereinafter referred to as Panhe Project), a high-tech industrialization demonstration project for the development and utilization of coalbed methane in southern Qin, aims to determine the coalbed methane productivity in this area through the development test of coalbed methane pilot well pattern, provide reliable technical and economic basis for large-scale development of coalbed methane, and realize the commercial development of coalbed methane.

The first phase of the project is completed in three stages. In the first stage, 40 wells were deployed for drilling and fracturing, drainage and production, and the ground construction project was completed at the same time. In the second stage, 60 wells are deployed and constructed; in the third stage, 50 wells are drilled and 1 10 wells are fractured.

The first phase of Panhe Phase I Project started drilling from June 5438+065438+1October 8, 2004, and completed the drilling task of 100 wells in July 2005. By the end of 2005 10, 40 wells had been fractured, drained and produced, and the ground construction project had been completed. In June 2005, the first phase of the project 1 65438+1October1was officially completed and put into operation. The company held a ribbon-cutting ceremony at Panhe site, announcing that the pilot project of Panhe had entered the commercial trial production stage, which also marked that China's coalbed methane industry had entered a new development stage.

This paper mainly makes a brief technical summary of 40 wells in the first phase of Panhe first phase project, including geological and reservoir characteristics, well pattern deployment, drilling, fracturing technology, drainage and gas production, surface construction engineering, etc., to exchange experiences with readers.

Geological and reservoir characteristics of 1

Panhe Project is located in panzhuang Block in the south of Qinshui Basin. The geological structure in this area is simple, the stratum is gentle, and the dip angle is 5 ~ 15. The secondary anticline is developed, showing a nearly north-south distribution. Zheng Zhuang anticline, Panhe syncline and Shigou anticline are developed in this area. A small fault was found in the south of Tongshuzhuang.

3 Coal is the target layer of this project. The coal seam is shallow, with a depth of 266 ~ 544m, with an average of 400m, a thickness of 5.20 ~ 7.2 1 m, with an average of 6.20m, containing1layer of gangue, with a thickness of 0.40 ~1.20m .. and a distance of1.

3. The coal has high metamorphic degree, high gas content and good gas quality. The coal belongs to anthracite, and the maximum reflectance of vitrinite is 3.59% ~ 3.70%. The gas content is 4.34 ~ 25.88m3/t, daf, with an average of 12m3/t, daf. Well PH 1-009 measured that the gas content of No.3 coal was 23.43m3/t, the daf, the methane concentration was 98.0%, and a small amount of CO2 and N2 were 0.38% and 1.62% respectively.

3. The coal permeability is 0.20~2.00mD, the reservoir pressure is 65438±0.97 MPa, the reservoir pressure gradient is 7.8 kPa/m. The reservoir temperature is 65438 08.8℃ (250.8 ~ 257.2 m).

The analysis shows that the syncline area in this area has high gas content and is a relatively rich area of coalbed methane. Gas content is an important factor to control single well production in this area. According to the production and production statistics, the single well production in syncline area is higher.

2 Well pattern deployment and optimization

Through numerical simulation, the well pattern is optimized. Combined with the production experience of Zaoyuan well group, this time, a five-point well pattern is adopted, which is arranged according to the well spacing of 300m×300m, and the control area of a single well is small. The actual well pattern orientation is determined as the direction of N60°E and the direction of N30°W, and wiring and well arrangement are carried out along these directions.

Principle of well layout: mainly from the aspects of gas bearing, resource conditions and geological conditions, combined with landform features, as a selection factor, select areas and locations with high gas bearing, high resource abundance, high exploration (control) degree, relatively open and flat terrain and suitable for road construction.

3 Application of new technology

3. 1 Done

The coalbed methane wells in Panhe Project are all vertical wells. Wellbore structure: the first spudding diameter is φ3 1 1. 15mm, the surface casing is φ 244.5mm The second spudding diameter is φ 215.9mm, and the technical casing is φ139.7mm.. ..

The first layer of the target coal seam, namely No.3 coal.

3.2 Drilling Technology

For the first time, air drilling technology was adopted on a large scale in Panhe Project. Air drilling has the advantages of high drilling efficiency, low cost and little pollution to coal seam, which overcomes the difficulty of equipment relocation in hilly areas.

At the same time, conventional mud rigs are also used for construction. Clean water drilling in coal seam section protects reservoir.

3.3 Increase production and transformation technology

This project mainly adopts hydraulic sand-carrying fracturing technology to transform coal reservoirs. At the same time, the "nitrogen foam fracturing technology", a scientific research achievement in the Tenth Five-Year Plan, has been successfully tested in the project, creating a new and efficient technology for increasing coalbed methane production.

Two wells, PH 1 and PH 1-006, were selected as test wells. The purpose is to explore suitable stimulation and reconstruction technology, improve formation seepage conditions and increase single well productivity. Before this, the compatibility of foam fracturing at night was studied, the surfactant fracturing fluid system without solid damage was selected, and the fracture calculation and construction simulation were carried out by using three-dimensional fracturing design software to optimize the construction parameters.

Nitrogen foam fracturing fluid has high viscosity and strong sand carrying capacity, which can effectively reduce the filtration of fracturing fluid in multi-fractured coal seams and control the development of fracture morphology. Less liquid consumption, less pollution to coal seam, fast back discharge after pressure and fast gas production. Foam fracturing well 1 ~ 2 days gas production. The test results show that the average daily gas production of two nitrogen foam fracturing wells, PH 1 and PH 1-006, is more than three times higher than that of active water and sand fracturing wells, and the gas production is stable at a high level, with remarkable stimulation effect. The average daily gas production of two nitrogen foam fracturing wells is 272 1m3. Therefore, the production of nitrogen foam fracturing wells is obviously better than that of conventional fracturing wells.

3.4 Explore the CBM drainage and production technology suitable for the reservoir and pay zone conditions in this area.

According to the characteristics of anthracite reservoir and pay zone, a set of drainage and production technology suitable for coalbed methane wells is explored. A set of process flow is put forward from the aspects of pump type selection, pump hanging structure design and surface single well flow. Formulate a reasonable drainage system, properly handle the relationship between liquid level, casing pressure and production, control a certain bottom hole pressure, maintain a reasonable pressure difference, control the outflow and blockage of pulverized coal, and control fracturing and sand return.

3.5 The automatic data acquisition system of coalbed methane field was built for the first time and applied to coalbed methane production management.

Its functions include: receiving, displaying and storing gas production signals and monitoring production conditions; Receiving equipment operation signals and monitoring equipment operation conditions; Remote monitoring of gas supply station, gas gathering station and valve group.

Through the automatic control system and remote monitoring system, all kinds of production data and the running state of main equipment can be completely transmitted to the control center, and all kinds of data can be displayed in real time and automatically stored on the TV wall. It can be uploaded to the company through the network, the station can be unattended, and the control center can respond quickly and deal with it in time in case of emergency.

4 Ground gathering and transportation project of coalbed methane field

The construction of ground gathering and transportation system in coalbed methane field fills the blank of coalbed methane industry in China.

The main projects include: single well station process flow and 4 sets of valve groups; Gas gathering station with daily pressurization of 80000m3 1 seat; ; One gas supply station with a daily compression of 80000m3；; There is a gas-fired power station with a daily output of 2 175 kW, and the total length of gas pipeline is about 4 1km.

Supporting works: 10 kV transmission line is 6.5km, 380 V transmission cable is 50km, signal transmission optical cable is 43. 1 km, an automatic transmission system and a remote monitoring system,1/colored steel house (32 rooms), slope protection and hydraulic protection, etc.

5 Commercial production and sales

By the end of 2005, Panhe Project had drilled 65,438+000 production wells, including 40 fracturing wells and 38 drainage wells.

The production results of drainage and production show that single well has high gas production, high casing pressure and low water production. The casing pressure of a drainage well is mostly 0.8 ~ 1.2 MPa, with an average gas production of 2000 m3/d, a maximum production of 7434m3/d and an average water production of 7m3/d. From July 2005 to the end of May 2006, the cumulative gas production was1kloc-0/60×/kloc. The initial drainage shows that this area has good coalbed methane productivity.

In 2006, 50 wells will be drilled, and 60 wells will be fractured and produced. By then, the annual production capacity will reach 1× 108m3.

6 conclusion

In only one year, Panhe Pilot Test Project completed the drilling and completion of 100 wells and fracturing of 40 wells, completed the construction of ground gathering and transportation project and started commercial production. At the same time, fruitful results have been achieved in geological and reservoir analysis and research, engineering deployment, well pattern optimization, drilling and completion technology, stimulation and reconstruction technology, drainage and production technology, and coalbed methane field gathering and transportation technology. Air drilling, nitrogen foam fracturing technology, gathering and transportation technology of coalbed methane field, automatic data acquisition system and other technologies are in a leading position in China, and many technical achievements are highly innovative, which has become a dazzling brilliance in the construction of Panhe demonstration project. It closely combines scientific research with engineering projects and becomes a model of combining scientific research with production.

The construction and successful commissioning of the Panhe demonstration project has enabled the company to enter the CBM development stage from the CBM exploration stage, which is also a milestone in the development of CBM industry in China. It is the achievements of the construction and commissioning of the Panhe demonstration project that have inspired and strengthened the confidence and determination of the leaders and engineers in the development of coalbed methane, and promoted and promoted the industrialization process of coalbed methane development in China.

Through the pilot project of Panhe River, remarkable achievements have been made in the development and deployment of coalbed methane, development engineering technology, ground gathering and transportation technology, drainage technology, sales and project management, reaching the purpose of national demonstration project and providing a good demonstration role for coalbed methane development in China. At the same time, it has played a leading role in the development of coalbed methane industry in China.

The start-up, construction and successful completion of the first phase of Panhe Pilot Project have condensed the courage and efforts of the new leaders of the company and the cooperation and support of all departments of the company. At the same time, the leaders, technicians and constructors of the cooperative units have also made indelible contributions to the construction and completion of this project. It is precisely because of the company's high degree of unity, full support, and the full cooperation of the construction unit that the Panhe pilot project was established.

refer to

China Petroleum and Natural Gas Group Company Drilling Contractors Association. 2004. Proceedings of Drilling Contractors Association [2004]. Beijing: Petroleum Industry Press.

[2] University of Alabama. 200 1 International Symposium on Coalbed Methane