Establishment of a quantitative index for evaluation of Caprock sealing, and application to the Shongliao Basin, China

Using basin modelling principles and methods, this paper puts forward a quantitative and comprehensive index (comprising the influence of a series of geological factors) to evaluate the sealing ability of a caprock, to establish the index with a computer modelling system, and to illustrate its value by application to the Shongliao Basin. The advantage of the Cap Rock Index (CRI) is that it can be used to calculate the oil and gas columns that could he sealed hy a caprock, to identify and grade caprocks, to recover sealing changes, and to evaluate the critical points at which caprocks start to seal oil and also gas in the geohistory evolution of a basin.