Aim at the present condition that the permeability of high rank coal reservoirs and its dynamic change regulation have been rarely studied,based on the modern testing technologies and actual measure data of Coalbed methane(CBM) well with better drainage effect in Qinshui Basin,using the international advanced CBM well numerical simulation software(COMET2),the dynamic change regulation of the permeability of high rank coal reservoirs during gas recovery has been discussed,using the gas and water recovery process in divided stage is matched.
The experiment indicated,that KCl mixed in CBM well fracturing fluid plays not only as antisweling agent,but it can also change adsorption properties and water wetability of coal matrix,resulted in increasing back-discharge rate of reservoir and decreasing reservoir damage.
The paper mainly describes the arrangement of equipments for drainage of CBM wells, the contents of production management and part of knowledge on safety, on the basis of perforation work and production management carried out in eight CBM wells, L1 - L8, of Liujia Coal Mine in Fuxin as well as experience with management obtained in the operation of CBM working site and from the petroleum mining industry
The technical difficulties for shallow coal bed gas wells cementing jobs under complicated conditions,and the exciting problems of the recent used mud system are analyzed. The characteristics the mud system for shallow coal bed gas well cementing should have are indicated.
To the feature of injection/down pressure testing and fracturing for separated layers in coal methane bed well,a new type combing pipe string of ZY plug + ZY221 packer has been developed and applied which successfully replaced the operation stem of using double packers to separate layers.
There were 73 168-m2 subplots on control sites; 42 subplots on secondary disturbances; 14 on major surface disturbances; eight on well pads; and seven on sites downslope of CBM wells water discharge points.
About 1314 percent of these CBM wells are on Federal lands while the majority are on State and private lands.
An additional attraction of CBM development is the low cost of drilling and completing CBM wells.
As of 2002, there were 3,250 active CBM wells in the Black Warrior Basin.
At this point all CBM wells have been vertical wells.