CAJ | 학술논문

鄂尔多斯盆地苏西地区盒8段及山1段为辫状河沉积，其含气储层与围岩纵波阻抗相近，利用常规叠后资料不能有效识别含气储层；同时，山1段砂体为中—弱振幅不连续地震反射，其同相轴无法在全区进行合理追踪，难以预测砂体的平面展布特点。针对以上问题，根据辫状河地质沉积特点，建立辫状河地震响应模式。利用含气储层和围岩泊松比差异明显的特点，尝试应用叠前AVO资料来识别含气储层。借鉴地震沉积学理论和方法，提出将AVO属性体岩性化，以便于后续的岩性解释。采用切片方法合理获取山1段砂体地震反射等时面。研究结果表明：正演和生产实践均验证了AVO属性体岩性化这一方法的合理性和实用性。应用该方法对研究区盒8段和山1段含气储层进行了有效的识别，具有等时意义的地震切片属性准确地反映了含气储层空间发育及平面展布特点。
악이다사분지소서지구합8단급산1단위변상하침적，기함기저층여위암종파조항상근，이용상규첩후자료불능유효식별함기저층；동시，산1단사체위중—약진폭불련속지진반사，기동상축무법재전구진행합리추종，난이예측사체적평면전포특점。침대이상문제，근거변상하지질침적특점，건립변상하지진향응모식。이용함기저층화위암박송비차이명현적특점，상시응용첩전AVO자료래식별함기저층。차감지진침적학이론화방법，제출장AVO속성체암성화，이편우후속적암성해석。채용절편방법합리획취산1단사체지진반사등시면。연구결과표명：정연화생산실천균험증료AVO속성체암성화저일방법적합이성화실용성。응용해방법대연구구합8단화산1단함기저층진행료유효적식별，구유등시의의적지진절편속성준학지반영료함기저층공간발육급평면전포특점。
The He 8 and Shan 1 members belonging to braided-river deposition are pay zones of Sulige western region, Ordos basin. The ranges of P-wave impedance of gas-bearing reservoir and surrounding rocks of these two members are overlapping. The gas reservoir could not be feasibly recognized by conventional post-stack seismic data. Also,due to the discontinuous mid-weak amplitude of seismic reflection,the seismic event of Shan1 member can′t be picked in the whole work area,leading to difficulty in obtaining the plane view of its sandstone distribution. Attempting to solve the problems above, we established the seismic response characterization of braided-river according to its sedimentary model. As the difference of Poisson ratio of gas-bearing reservoir and surrounding rocks are distinct,the AVO seismic data were utilized to identify gas-bearing reservoir. The conception of lithological converting has been proposed with reference to the theory of seismic-sedimentology. The AVO attribute volume was converted to lithological volume,which provides convenience for the subsequent interpretation work. The isochronous surface of Shan1 member seismic reflection can be obtained with the aid of slicing method. The result shows that the feasibility of lithological converting of AVO attribute volume has been demonstrated by forward modeling and practical application. This series of method is capable of recognizing gas-bearing reservoir of He 8 and Shan 1 members,and the evolutional history and plane distribution character of the gas-bearing reservoir are clearly delineated by the slices with isochronous significance.