CAJ | 학술논문

川西坳陷须（须家河组）五段天然气资源量巨大，具有良好的勘探开发远景；但地质认识程度低，尤其针对气藏各向异性的研究极少。为了提高储层预测精度和井位部署成功率，针对须五段开展各向异性研究，有利于进一步认识须五段储层特征并深入分析天然气聚集规律。通过早期研究发现，受四川盆地须五时期的沉积环境控制，川西坳陷须五段形成了以厚泥页岩和薄致密砂岩为主体的岩性组合，页岩层横向变化大，加之页岩矿物成分、碎屑颗粒定向排列、周期性薄层沉积及其他非均质特性，导致了地层展现出各向异性特征。目前，分析预测地层空间各向异性的有效方法并不多，且大多数方法仍然以地震数据为基础：通过分析地震反射及分方位地震属性对岩石类型、物理性质及构造形态等特征的直观响应，实现岩层各向异性指示信息的准确提取。相比较而言，如果不采用分方位地震数据，而仅基于全方位叠加地震数据的各向同性分析方法，则忽视了页岩的各向异性本质，不利于地质问题的准确认识。文中采用上述方法思路，基于分方位与全方位叠加地震数据，对比分析了这两类数据的地震反射响应特征、曲率体属性、相干体属性和储层阻抗等参数，并在地震各向异性信息的指示下捕捉岩层空间变化特征，成功地实现了川西须五段气藏沉积相、岩性、裂缝的精细解释和“甜点”储层的高精度预测。
천서요함수（수가하조）오단천연기자원량거대，구유량호적감탐개발원경；단지질인식정도저，우기침대기장각향이성적연구겁소。위료제고저층예측정도화정위부서성공솔，침대수오단개전각향이성연구，유리우진일보인식수오단저층특정병심입분석천연기취집규률。통과조기연구발현，수사천분지수오시기적침적배경공제，천서요함수오단형성료이후니혈암화박치밀사암위주체적암성조합，혈암층횡향변화대，가지혈암광물성분、쇄설과립정향배렬、주기성박층침적급기타비균질특성，도치료지층전현출각향이성특정。목전，분석예측지층공간각향이성적유효방법병불다，차대다수방법잉연이지진수거위기출：통과분석지진반사급분방위지진속성대암석류형、물이성질급구조형태등특정적직관향응，실현암층각향이성지시신식적준학제취。상비교이언，여과불채용분방위지진수거，이부기우전방위첩가지진수거적각향동성분석방법，칙홀시료혈암적각향이성본질，불리우지질문제적준학인식。문중채용상술방법사로，기우분방위여전방위첩가지진수거，대비분석료저량류수거적지진반사향응특정、곡솔체속성、상간체속성화저층조항등삼수，병재지진각향이성신식적지시하포착암층공간변화특정，성공지실현료천서수오단기장침적상、암성、렬봉적정세해석화“첨점”저층적고정도예측。
The huge gas potential in the 5 th member of the Xujiahe Formation has made it one of the hottest exploration targets in China .However ,the formation has not been well explored and many geological “mysteries” remained unsolved-anisotropy of the gas reservoirs there is one of them .A research was carried out on the anisotropy to better understand the reservoirs features and accumulation patterns , so as to improve the precision of reservoir prediction and success rate of well drilling .Previous study shows that the member had been controlled by sedimentary environment and formed lithologic assemblage dominated by thick mudstone and shale and thin tight sandstone .Looking horizontally ,the shale varies drama-tically and shows strong anisotropy due to complicated mineral combination ,directional alignment of detrital grains ,cyclic veneer and other heterogeneous features .There have had no effective method for analyzing and predicting the anisotropy so far.Available methods are mostly based on seismic data to obtain anisotropy information of rocks through analyses of seismic reflection and the direct responses of azimuth attributes upon rock types ,physical features and structure configura-tions.Comparatively speaking ,anisotropy feature of shale formations is likely to be ignored by isotropy analyses based solely on stacked wide-azimuth seismic data .By combining both the azimuth and wide-azimuth stacked seismic data ,we compared and analyzed the seismic reflection responses ,curvature attributes ,coherence attributes and impedances of the two sets of data ,and then captured features of reservoir space under the guidance of the anisotropy information .A fine in-terpretation of sedimentary facies ,lithology and fracture of the reservoirs and an accurate prediction of sweet spots in the member were then achieved by applying the above-mentioned method and data yield from it .