Synthesis of a Flexible Particle as a Lost Circulation Material in Drilling Fluids

Lost circulation is always a worldwide problem which is difficult to solve in the process of oil and gas exploration and development. In recent years, lots of lost circulation materials (LCM) and technical aspects of the research work have been made at home and abroad. However, most LCM cannot has good deformability, swelling, temperature resistance, salt resistance and other properties at the same time, resulting in poor lost control and repeated leakage occurred. In order to solve the defects of these LCM, the flexible particle lost circulation material for drilling fluids was developed. The lost circulation material is designed from molecular structure. Through the orthogonal experiment, a flexible particle lost circulation material with a temperature resistance above 150 degrees C is developed. And the swelling increasement of the lost circulation material increased by7 times in salt water, and it had better water swelling and toughness at high temperature. And at the same time, the water swelling of the lost circulation material has a certain delay. The matching between the particle size of the flexible particle lost circulation material and the sand bed is studied to determine the optimum particle size of lost circulation material.