Paper: LOST CIRCULATION SOLUTIONS FOR PERMEABLE AND FRACTURED FORMATIONS

Loss of drilling fluid to the formation is one of the most costly problems that drillers face during well construction. Common methods used in the past involved incorporating materials in the fluid or in pills to bridge permeable or fractured formations and create filter cake over these bridges. Current technology enables a comprehensive approach that complements these methods but emphasizes other aspects of the drilling operation. These include making use of drilling fluids that inherently reduce the rate of loss of fluid through modification of fluid properties like low-shear-rate viscosity; minimizing fluctuations in the fluid's equivalent circulating density; accurately modeling the rock mechanics of the formation; and strengthening the wellbore. Implementation of these techniques will be discussed, along with their impact in current drilling operations.