Adaptive leak preventing and stopping agent for drilling fluid

Abstract

The present invention discloses one kind of adaptive leak preventing and stopping agent for drilling fluid. The adaptive leak preventing and stopping agent consists of pre-cross linked polymer grain in 30-60 weight portions, plant fiber in 10-40 weight portions, olefin polymer in 10-20 weight portions and calcium carbonate in 5-20 weight portions. By means of the synergistic effect of the ingredients, the adaptive leak preventing and stopping agent bridges, links, fills and reinforces in the leak passage to form plugging layer, raise the pressure bearing capacity of the stratum and reach the aim of preventing and stopping leak. The adaptive leak preventing and stopping agent with elastic and deformable components is suitable for plugging pores and cracks in relative large range and can reach effective leak stopping.

Description

Technical field: [0001] The invention belongs to an anti-leakage plugging agent for petroleum drilling fluid. technical background: [0002] Lost circulation is one of the most serious complex situations in the oil drilling process. The occurrence of lost circulation will bring inconvenience and loss to the drilling project, consume drilling time, lose drilling fluid and plugging materials, and cause pipe sticking, blowout, and well collapse. A series of complex situations, such as drilling, even lead to the scrapping of the wellbore, and also cause damage to the oil layer, resulting in major economic losses. [0003] At present, the most widely used and low-cost plugging agent is bridging plugging agent. The bridging plugging agent needs to select a reasonable particle size of the plugging agent according to the size of the cracks or pores in the lost formation, and the particle size of the plugging agent is strictly dependent on the size of the pores or cracks in the leak...

AI Technical Summary

Problems solved by technology

Although the fracture or pore size of the formation can be obtained by coring analysis and logging data interpretation, it is difficult to accurately grasp the fracture width of the lost formation due to the influence of the number of cores taken, incomplete logging data and formation heterogeneity Or pore size, which is the main reason for the low leakage prevention and plugging success rate of bridging plugging agent