大型油气藏重力异常提取组合技术

Combined extraction technology of gravity anomaly of large reservoir

在分析各类油气藏基本特征的基础上,建立背斜、断层、尖灭和岩体刺穿组合复杂油气藏理论模型,运用趋势分析、差值切割、小波分析和细胞神经网络等识别方法提取油气重力异常信息,通过对比各种方法的优劣,形成一套基于油气成藏模式进行油气藏重力信息提取的组合技术。通过对三湖坳陷涩北地区的实际资料处理,辅以重震联合解释、重力异常正则化下延和视密度成像技术,验证了异常提取组合方法的有效性。结果表明,该技术可以克服单一提取方法的缺陷,提高异常提取的可靠性,减少油气预测的多解性。

Based on the analysis of basic characteristics of various types of oil and gas reservoirs, some kinds of theoreticalreservoir models were established considering four complex reservoirs that include anticlines, faults, pinchout and rock bodypiercing. Four identifying methods, i. e. trend analysis, difference cutting, wavelet analysis and cellular neural network wereused to extract oil and gas gravity anomaly information. These methods were compared and then a combined extraction tech-nology was formed based on the oil and gas reservoir model. The effectiveness of the combined extraction method was verifiedby processing actual data in Sebei, Three-lake region. The results show that the new method overcomes many shortcomings inpopular single extraction methods, improves the reliability of the anomaly extraction, and reduces multiple solutions in the oiland gas prediction. The robustness of the combined extraction method was verified by comparing multiple techniques combi-ning gravity and seismic joint interpretation technology, gravity anomaly regularization downward-continuation technology andapparent density imaging technology.