Pressure prediction in nearly balanced drilling and oil and gas prediction

The technique of pressure prediction is mainly to calculate formation pore pressure and pressure coefficient with seismic interval velocity, and based on it, reasonable density of drilling fluid is designed, thus nearly balanced drilling is realized. At the same time, a low velocity and abnormal high pressure zone is determined to discriminate the position of oil and gas formation based on the relationship of intersection. The technique has been used in Zhongyuan oilfield since 1988, 120 of major exploration wells and adjustment wells are predicted , oil and gas predictions of nearly balanced drilling and pre-drilling are realized , by which large number of drilling costs are saved , drilling accidents of blowout and well kick and reservoir pollution are prevented, thus smooth production is guaranteed.