Predicting Abnormal Formation Pressure Using 3D Seismic Velocity, in Kupal Oil Field

Pore pressure prediction is important in hydrocarbon exploration, production, and drilling activities. The presence of abnormal pressure may cause different problems such as pipe stuck, well blow out, mud loss, and so forth. Using seismic data is the only method for pore pressure prediction before drilling. In the present paper, stacking velocity which has been obtained from 3D seismic data processing was calibrated with acoustic log. The effective pressure was determined using Bower´s equation. Pore pressure would be predicted by overburden pressure and basic Terzaghi´s equation as well as abnormal pressure zones if existed. The results indicated that there have been two abnormal pressure zones existed in the Kupal Oilfield: high pressure zone in Gachsaran Formation (Member 1 or cap rock), in Pabdeh Formation, and two low abnormal pressure zones in the upper part of Asmari Formation. Pore pressure in Lower Asmari section is higher than in the upper part due to higher porosity.