The Application of Potassium and Calcium Based Organic Salt Drilling Fluid System in Mo 116 Well Area

Mo 116 well block structure is located in Junggar basin with complex geological conditions,high gypsum and montmorillonite content. In the process of drilling the main difficulties are: the long open hole section in Tugulu formation has a large section of the mudstone,and is easy to swell,causing shrinkage and sticking; west Shanyao kiln group would easily collapse and fall,and there is leakage risk; Sangonghe group formation pressure system is complex with high pressure gas layer. To solve these problems,we applied potassium calcium base organic salt drilling fluid system,which has many advantages,such as strong inhibitory,good rheological property,low fluid loss amount,and good capacity of bringing debris. Meanwhile,this system could reduce the accidents and improve the rate of penetration and electric log.