DISCUSSION ON TIGHT SANDSTONE GAS RESERVOIR DEVELOPMENT BY GAS DRILLING

Tight sandstone gas reservoir is a very important unconventional petroleum resource.Its characteristics are tight rock,small pore-throat,powerful reforming effects of clay minerals,strong water wettability and low initial water saturation.It is badly damaged and restored difficultly when the reservoir is drilled by drilling fluid,gas well productivity is reduced greatly.Gas drilling is an effective technique of formation damage control,high productivity and good effect are gotten in development of tight sandstone gas reservoir by this technique in China,but the results of some wells are bad,and downhole complex problems are taken place.Tight sandstone gas reservoir has strong nonuniformity,in order to full bring into play the advantage of gas drilling,the fine description of gas reservoir was done,the main controlling factors of reservoir must be analyzed synthetically,the distribution pattern of high permeability and abundance zone is established,well location and wellbore trajectory are optimized,all these are the material base of high productivity well.Because there is defect in gas drilling,and the argumentation of gas drilling engineering feasibility must be done.In order to control formation damage and put into production quickly,the design of gas drilling and well completion was make up integration;and the management and operation of field test were strengthened according to the technic characteristic of gas drilling,thus the high productivity of gas well was achieved.