【论文题目】 Effective stress, porosity, velocity and abnormal pore pressure prediction accounting for compaction disequilibrium and unloading
【论文作者】 Jincai Zhang
【刊物】 Marine and Petroleum Geology
【时间】 Article history:Received 30 July 2012
Accepted 15 April 2013
Available online 25 April 2013
【内容简介】 Pore pressures in subsurface formations vary from hydrostatic pressures (normal pore pressures) to severe overpressures (more than double of the hydrostatic pressures). Overpressures exist in many geologic basins in the world. If this abnormal overpressure is not accurately predicted before drilling and while drilling, it can greatly increase drilling risks and incidents. For examples, in deepwater of the Gulf of Mexico, incidents associated with pore pressure and wellbore instability accounted for 5.6% of drilling time in non-subsalt wells, and 12.6% of drilling time in the subsalt wells (York et al., 2009). The abnormally high pore pressures also caused serious drilling incidents, such as the fluid kicks and well blowouts (Skalle and Podio, 1998; Holand and Skalle, 2001). Therefore, pore pressure prediction is critically important for drilling planning and operations in oil and gas industry. Abnormally high pressures also induced geologic hazards and disasters, such as weakness in faults (e.g., Bird,1995; Tobin and Saffer, 2009) and mud volcanoes (Davies et al., 2007; Tingay et al., 2009).
