砂砾岩储层中黄铁矿的油气地质意义——以准噶尔盆地车60井区齐古组为例  

Petroleum geological significance of pyrite in glutenite reservoirs:a case of Qigu Formation in Che 60 well field,Junggar Basin

作　　者：熊连桥[1,2] 于福生[3] 姚根顺 高崇龙 王玉[4] 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油杭州地质研究院,杭州310023 [3]中国石油大学(北京)地球科学学院,北京102249 [4]中国石油新疆油田分公司采油一厂,新疆克拉玛依834000

出　　处：《岩性油气藏》2017年第4期73-80,共8页Lithologic Reservoirs

基　　金：国家自然科学基金项目"同生逆断层对冲积扇沉积构型的控制作用机理"(编号:41372116);中国石油集团重大科技专项"深层油气勘探开发关键技术研究"(编号:2014E-32-09)联合资助

摘　　要：准噶尔盆地西北缘车60井区齐古组砂砾岩储层中发育大量晶型完好的自生黄铁矿,且集中发育于泥质含量低、储层物性好、含油饱和度高的辫状河三角洲砂体中。前期基于测井响应特征的研究将这些发育黄铁矿的层段解释为泥岩隔夹层,直接导致对储集砂体连通关系与剩余油分布规律等认识出现偏差,遗漏了油藏内具有油气储量挖掘潜力的部位。利用测井资料结合岩心观察,建立了研究区黄铁矿发育砂体的识别图版;基于三维地质建模技术,结合区域地质背景建立了研究区黄铁矿的形成模式。在此基础上,根据等效体积模型对黄铁矿发育砂体的孔隙度进行了重新解释,并计算了砂体中黄铁矿的含量。研究表明,该区黄铁矿的分布受断层控制,同时砂岩储层中的黄铁矿可以指示含油砂体的分布,并非为泥岩层或隔夹层;利用等效体积模型得到的黄铁矿发育砂体孔隙度比原解释模型更接近岩心实测分析数据;这些砂体可成为剩余油的聚集区或储量挖潜区。该研究结果可丰富对黄铁矿的认识并对剩余油分布研究或油田注水开发具有重要的指导意义。A large number of authigenic pyrites with perfect crystalline were found in the glutenite reservoirs of Jurassic Qigu Formation in Che 60 well field, northwestern margin of Junggar Basin. These pyrites were concen- trated in the braided river delta sandbodies with low shale content, high oil saturation and good physical proper- ties. However, strata with pyrite were interpreted as shale intervals in the previous studies based on the well log- ging interpretation, which directly led to the misunderstanding of sandbody connectivity and remaining oil distilbution and resulted in the omission of potential oil and gas reserves in the reservoirs. Based on well longing data and core observation, identification charts of pyrite-rich sandbodies were established, and combined with the geo- logic settings of the study area, 3 D geological modeling technique was applied to establish the formation model of pyrite. And then porosity and pyrite content of the pyrite-rich sandbodies were recalculated through equivalent volume model. The results show that the distribution of pyrite-rich sandbodies was controlled by faults, and py- rite in the glutenite reservoirs could indicate the distribution of oil-bearing sandbodies, and these sandbodies are not shale intervals. The porosity obtained from the equivalent volume model was much closer to the data of core sample analysis than the old interpretation model. These pyrite-rich sandbodies might be the favorable accumulations of remaining oil or potential areas of reserves. This result could enrich the understanding of pyrite and it is significant for the study of remaining oil and the oilfield flooding development.

关 键 词：砂砾岩储层 黄铁矿 识别图版 等效体积模型 齐古组 准噶尔盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]