DRILLING CHALLENGES AND TECHNICAL SOLUTIONS FOR XIANGGUOSI UNDERGROUND GAS STOREROOM

Xiangguosi underground gas storeroom is the first building underground gas storeroom in Southwestern area in China. It is a typical carbonate gas reservoir. The gas storeroom would work for long time,and the injection wells would be needed for powerful injection and production,and would make a circulation periodically,and other special requirements would be wanted,which needs exact injection hole integrality. In addition to well geometry integrality,currently,there are several different pressure gradient,which are less than 1.0,shallow formation is old,but easy to cause loss,typical high deviated stratum,strong building capacity while rotary drilling,loss and collapse together while drilling,coal and gypsum,the gas field is in the beauty spot and natural protecting zone,all these factors would result in extreme difficulties in safe drilling. Compared with drilling challenges in the reservoir,this paper put forward solutions,which included optimal well geometry,optimal gas drilling methods,reasonable cluster arrangement,optimal well trajectory,external completion packers and flex slurry,screens preventing sands in completion. As soon as this gas reservoir is set up,it must play very important model role in reservoir construction in southwestern area,and provide good technical support.