川东北地区礁滩相储层预测技术与应用

Reservoir prediction technology of reef-flat facies in northeast Sichuan province and its application

（1.成都理工大学能源学院，四川成都610059；2.中国石油化工股份有限公司南方勘探开发分公司研究院，云南昆明650200）

College of Energy Resources, Chengdu University of Technology, Chengdu 610059, China

随着地质认识的深入和勘探思路的转变，川东北地区在原来认为是勘探不利区的海槽相区，相继发现了飞仙关组鲕滩孔隙型气藏、长兴组礁滩孔隙型气藏，探明了普光特大型气田。钻探表明，川东北地区长兴飞仙关组气藏多为构造岩性复合型气藏，加强储层预测研究是取得勘探成功的关键。为此，在达县宣汉地区利用高分辨率三维地震资料，采用古地貌分析、地震相分析和多属性分析技术进行了礁滩相储层展布预测；应用地震波阻抗反演方法、岩性反演方法对礁滩相储层孔隙度、有效厚度进行了定量预测。在长兴组和飞仙关组预测储层发育区，毛坝3井、普光5井、普光6井均钻获长兴组礁滩相优质储层，完井测试获高产天然气流；大湾1井、大湾2井钻获飞仙关鲕滩优质储层：预测结果与钻探结果吻合。将以上方法技术应用于通南巴构造带和元坝地区，预测元坝地区可能发育大规模的礁滩相储层，是勘探有利区。

Northeast region of Sichuan province was formerly regarded as trough facies, and was not beneficial to prospecting. But now, many gas reservoirs has been discovered in this region, including oolitic-beach porous gas reservoir of Feixianguan group, reef-flat porous gas reservoir of Changxing group and Puguang oversize gas field. The exploratory drilling shows that the gas reservoirs of Changxing-Feixianguan group in northeast Sichuan province are most of structural-lithological gas reservoirs. The key of successful prospecting is the continual study of reservoir prediction. Therefore, in Daxian-Xuanhan area, high-resolution 3-D seismic data was utilized to predict the distribution of reef-flat reservoirs, along with the techniques of paleogeomorphology analysis, seismic facies analysis and multi-attributes analysis. Impedance inversion and lithological inversion were used to quantitatively predict the porosity and effective thickness of reef-flat reservoirs. In the predicted reservoir-developed region of Changxing-Feixianguan group, good reef-flat reservoirs of Changxing group have been drilled in well Maoba3, well Puguang5 and well Puguang6. High-production natural gas flow has been obtained in drilling test. Good reef-flat reservoirs of Feixianguan group have been drilled in well Dawan1 and Dawan2. The actual drilling results coincide with the prediction results. The above method was applied in Tongnanba srtuctural belt and Yuanba region. This predicts that largescale reef-flat reservoirs may develop in Yuanba region and be beneficial to prospecting.