The Main Control Factor Research Of Capacity Of CBM Vertical Well In Wubu Area

Capacity is the conclusion of coal bed methane developing on the ground. The capacity of CBM vertical well is the result of cooperation of geological factors and engineering factors. From viewpoint of systematology, based on Wubao original geological data and engineering data, on the base of studying gas bearing characteristics, adsorption characteristics, physical properties, hydrogeologic conditions and so on, reviewing the methods of rock mechanics and fractal geometry, quantitatively evaluating coal deformation with intensity factor and the fractal dimension, this paper identified the spatial distribution law of coal reservoir original permeability. And according to logging curves, classifying coal body structure, analyzing wellbore enlargement by rock mechanics means, the conclusion is that wellbore enlargement become smaller when intensity factor increases and drilling density affected wellbore enlargement the most in the third type of coal. According to the principle of hydraulic fracturing, this paper set up permeability prediction model to predict the permeability of this area after a hydraulic fracturing. Capacity of the main controlling factor was studied in this area form the aspects of well drilling and completion, fracturing, extraction in the working system and so on. The results showed that extraction in the working system largely controlled capacity and a rational extraction working system could improve capacity of the coal bed methane wells. This paper studied the capacity of the main controlling factor in Henggou area. The study would be conducive to coal-bed gas exploitation of this area, and meanwhile could offer some suggestions to Henggou's coal-bed gas exploitation.