Panjiang Mining Area Coalbed Methane Development and Utilization ProjectAn Introduction By Chen Fuqing Chief Engineer Panjiang Coal

Panjiang Mining Area Coalbed Methane Development and Utilization Project An Introduction

By Chen Fuqing Chief Engineer
Panjiang Coal & Electric Power (Group) Corporation

1. Project Initiation
Coalbed methane is a clean energy. Development and utilization of coalbed methane is of great social and economic benefits for it not only protects the environment but also adds to the new energy. It also helps ensure safety in coal mines and readjust the industrial structure in the coal mining industry.

Panjiang mining area has coalbed methane resources totaling over 124.3 billion m3. A great deal of work has been done in this mining area over the recent years for the development of the coalbed methane and some certain progress has been obtained so far. However, due to the lack of funds the development has been slow and a yearly 30.0 ~ 35.0 million m3 of coalbed methane of high concentration has been released into the atmosphere which is a big waste of resources and damage to the environment. At such a moment, development and utilization of coalbed methane in Panjiang mining area appears to be important and necessary.

2. General Conditions of Panjiang Mining Area
Panjiang mining area is located within the boundaries of Panxian county, Liupanshui city at the western borders of Guizhou Province. Its west side is bordered with Fuyuan county of Yunnan Province. The state highway No.320 runs through the mining area. Shui-Pan highway, a branch line of Nanning-Kunming railway and Shui-Bai railway, which is now under construction also runs through the mining area, giving great convenience of transport in this area. Within the mining area, there are a total of 28 mine fields with a total strike length of 251.96km, inclination width of 2.6km and a total area of 649.11km2. Perspective coal reserves are 38.3 billion tons and it is mainly contained in the upper longtan group in the Permian strata. The thickness of the coal bearing measure is 220 ~377m with a total of 20 ~ 60 coal seams, of which 10 ~ 15 are mineable seams with a total mineable thickness of 15 ~ 30m at a dip angle of 10 ~ 300. This mining area is a highly gas concentration area and coal/gas outburst prone mining area.

3. Occurrence of Coalbed Methane and Amount of Resources
3.1 Coalbed methane occurrence
Based on the geological survey data and coal mine coalbed methane occurrence parameters testing results, coalbed methane pressure in coal seams within the depth of 500m is between 0.495 ~ 1.32 Mpa with the pressure gradients of 0.00395 ~ 0.0102 Mpa/m and the permeability of coal is up to1.67md. Most of the coal seams are in the category of extractable and easy-to-extract coal seams. Coalbed methane content in coal is between 10 ~ 20m3/t, the concentration gradients is 0.00844 ~ 0.0352m3/t/m. Coalbed methane pressure and content become greater with the increase of depth of coal seams.

3.2 Coalbed methane resources
Coalbed methane resources in Panjiang are very rich. The total coalbed methane within the depth of 500m in Panjiang mining area is 124.3 billion m3, not including the CBM resources in the deeper part. The coalbed methane resources calculated here do not include that in the rock strata and the gob areas of the existing mines. This is the reason that the resources are not very big.

4. Coalbed methane extraction operation
A total of 10 wells equipped CBM extraction stations have been set up in Panjiang mining area. Equipment used are as follows: 2 sets of type SK-120 pumps, 22 sets of SK-85 pumps and 4 sets of type SK-60 pumps. All extraction stations are equipped with two sets of both high- and low-negative pressure extracting systems. Total length of 200 ~ 350mm extraction pipeline is 35.3km and the annual extraction capacity is well over 600 million m3. The extraction station of Jinjia mine is just under construction and its CBM extraction in 1999 is registered at 37.7825 million m3. Extraction rate of all extraction stations is stabilized at around 5 ~ 10m3/min and above with the highest being 17m3/min. Extraction rate is over 20% for entire mines and this rate is as high as 60 ~ 70% for coal faces. It is expected that in the year 2000 a total of 40.0 million m3 of CBM could be extracted. For the time being, the purpose of CBM extraction is mainly for the sake of coal mine safety. If CBM is extracted as a resources development and pre-extraction is carried out in all of the six existing productive mines, the annual extraction could be totaled at more than 150.0 million m3. If extraction through surface drilling is carried out completed with pre-drainage from within the mines, the annual CBM extraction could be well over 500.0 million m3.

5. Utilization of Coalbed Methane
Construction of CBM civilian utilization system in Panjiang mining area started in 1986 and by 1998 the CBM civilian utilization systems in Shanjiaoshu mine, Yueliangtian mine are completed. Each of the systems is completed with a CBM storage tank with storing capacity of 10,000m3. Now, more than 2,000 households in Shanjiaoshu mine residential area and the canteen have begun the use of CBM fuel while in Yueliangtian mine a total of more than 1,500 households and the canteen have begun consuming CBM as fuel.

Feasibility study is under way for the coalbed methane utilization projects of the six producing mines in Panjiang mining area. The feasibility study is now implemented by Guizhou Provincial Coal Mine Design Institute. This project has been agreed upon by the Guizhou Provincial Economic and Trade Commission and Guizhou Provincial Coal Bureau. The approving document is Qian-Jing-Mao-Gai-Zi No. [2000] 532. It is agreed by the document that a total of 51.0 million yuan of investment be put into the first phase of the project to achieve a CBM supply capacity of 75.0 million m3/a. This is designed for fuel gas supply to residential households both within the mining area and in the peripheral area and boilers, canteens, hospitals, schools and office buildings within the mining area.

6. Development of the Second Phase Project
Located in-between Guiyang city of Guizhou Province and Kunming city of Yunnan Province, Panjiang mining area is 350km from Guiyang city, 320km from Kunming city, 130km from Qujing city and 30km from Fuyuan county. For details see the attached map.

Kunming city, the capital of Yunnan Province, has a total population of 4.67 million in 1.50 million residential households. Both Qujing county and Fuyuan county has a population of 0.60 million in 0.20 residential households. The six producing coal mines in Panjiang mining area are extracting CBM gas at an annual rate of over 150.0 million m3 by regional pre-extraction from mines completed by drainage from the gob areas in the mines. Calculated on the basis of each household daily gas consumption of 1m3/d of pure CBM, with the gas consumption of 35.0 million m3 within the mining area, the remnant 115.0 million m3 of CBM gas can fully satisfy the needs of gas fuel consumption by the residential households in Fuyuan county and Qujing city. To achieve this purpose, a total of around 390.0 million yuan of investment is needed to connect the first phase of CBM civilian utilization project of the six producing mines to transmit the remnant CBM fuel gas to Qujing and Fuyuan for civilian consumption. The annual turnover could be as high as 150.0 ~ 200.0 million yuan. If large scale development is carried out, the coalbed methane developed could be sent to the city of Kunming. With the forming of such a powerful CBM industry, greater social and economic benefits could be created as a result.

In addition, power generation by firing coalbed methane is also a new industry that could produce much higher economic benefit. Panjiang mining area has now completed its private power grid with an annual power consumption of more than 300.0 million kWh. It is expected that by 2010 the power consumption could be as high as 500.0 million kWh. Under the conditions of coalbed methane development merely from the coal producing mines and district pre-extraction and drainage from gob area are adopted for CBM production, the annual CBM extraction could be as high as over 150.0 million m3. With the amount consumed for civilian purposes within the mining area deducted, there will be 115.0 million m3 left. Calculated on the basis of 1m3 of pure CBM be converted into 3 kWh of electric power, an annual total of 345 million kWh of power can be generated. To achieve this, an electric power plant with a capacity of 40MW could be constructed. Based on the local electricity price of 0.35 yuan/kWh, the project’s annual turnover could be as high as more than 120.0 million yuan. If CBM development and utilization is further intensified, the increased power generation will not only satisfy the needs of the mining area, the remnant power generated can also be supplied to the local power grid. One thing is very clear that the construction of CBM fired power plant only requires comparatively limited investment and shorter leading time, while the economic benefits produced could be much higher.

In the light of the above introduction, it can be concluded that Panjiang mining area is rich in CBM resources and the market prospect is very promising. The investment environment here is ideal and the potential of economic benefit is high. We warmly welcome investors from both home and abroad to invest in CBM development and utilization projects in Panjiang and we equally hope that governments at all levels provide us with sufficient assistance and usher us to more friends from both China and abroad.