Seismic Evaluation Method for Fault Sealing：a Case of Yingdong in Qaidam Basin

Evaluation for fault sealing in accumulation research on complicated fault-block reservoir has a very important role. The fault gouge ratio (SGR) algorithm defined by Yielding et al in 1997 is usually used to evaluate the thin sand-shale formation. As part of the evaluation parameters in SGR from the logging data, it makes this method have two limitations: First, the method has certain requirements to exploratory well number and distribution positions; second, the method can’t extrapolate plane fault sealing. Aim at the above two questions, taking Youshashan fault in Yingdong oilfield for example, forecasting plane fault sealing by four steps: First, obtaining the lithology information by gamma inversion; second, through the calibration of logging interpretation and inversion results, establishing a quantitative relationship between the inversion results and shale content; third, calculating the fault gouge ratio (SGR) by inversion results in the vicinity of any fault; four, after calculating plenty of SGR of samples, and then forecasting plane fault sealing. Because of complexity of fault structure and limitation of data, forecasting plane fault sealing by using seismic techniques combined with geological method tentatively providing a new method for evaluation of fault sealing of oil and gas reservoir.