Research on Non-reservoir Horizontal Well Development Technology of Zhijin Coalbed Methane Reservoir in Guizhou Province

Abstract:

Drilling and fracturing come to high cost for vertical well in coalbed methane development with small control area and low production rate of single well; while for horizontal wells in coal seam, drilling is difficult with high risk and wellbore trajectory control is difficult in thin coal seam, the harmful solid in drilling fluid has serious reservoir damage and the recovery factor is low. Based on the above, this paper analyzes the geological structure of coal measures in Zhijin block of Guizhou and puts forward a new way that horizontal wells are laid in stable non-reservoir of coal measure strata to get through the coal seams above and under the horizontal wells by hydraulic fracturing for multi coal seams development at the same time. Compared with the conventional development mode, the horizontal wells in non-reservoir have the advantages of small drilling risk, light reservoir damage and high production of single well; and at the same time, coal measure tight gas and shale gas can be developed to improve utilization ratio of unconventional gas. The research on the development technology of Guizhou Zhijin coalbed methane in non-reservoir with horizontal wells provides new way to solve the difficult development of coalbed methane in Guizhou coal measures strata with the characteristics of many thin coal seams and small interlayer spaces as well as the utilization of coal measures gas.