古冲沟地貌控制辫状河型冲积扇沉积特征及有利储层评价  

Sedimentary Characteristics and Favorable Reservoir Evaluation of Braided Fluvial Alluvial Fan Controlled by Paleo Gully Geomorphology

作　　者：孙宜丽[1] 樊晓伊 Sun Yili;Fan Xiaoyi(Sinopec Henan Oilfield Company,Nanyang,Henan 473132,China;Henan Provincial Key Laboratory of Enhanced Oil Recovery,Nanyang,Henan 473132,China)

机构地区：[1]中国石化河南油田分公司,河南南阳473132 [2]河南省提高石油采收率重点实验室,河南南阳473132

出　　处：《特种油气藏》2023年第3期29-37,共9页Special Oil & Gas Reservoirs

基　　金：中国石化重点项目“春光探区成藏精细研究及目标优选”(P19016-2)。

摘　　要：受古冲沟地貌控制的冲积扇,其地层空间叠置样式、沉积特征更为复杂,难以用现有模式指导沉积特征研究。以现代白杨河冲积扇研究成果为指导,结合地震、岩心、测井、物性、含油性等资料,对春光油田沙湾组古冲沟地貌控制下的辫状河型冲积扇,开展了古地貌、岩相特征、微相展布等沉积特征的系统性研究,建立动态沉积演化模式。研究结果表明:该区具有双通道古冲沟地貌特征,地层经历冲沟—填平—进积—退积的充填过程,具有不均衡沉积特点;受区域位置所限,仅发育扇中和扇端沉积亚相,早期为洪水期,以沉积作用为主,受古冲沟地貌控制,发育限制性的水道化扇体沉积,从扇中到扇端,具有重力流向牵引流沉积特征,晚期为洪退期,随着地层的填平补齐,发育非限制性的扇形沉积体,以漫流沉积为主;在沉积微相精细识别的基础上,建立储层分类评价标准,将研究成果应用于春光油田西北部,筛选出3个有利区,部署新井在古冲沟型冲积扇油藏中获得突破。研究成果丰富了对不同地貌控制的冲积扇沉积演化特征的认识,对古冲沟型冲积扇沉积特征研究有重要意义。The stratigraphic space stacking pattern and sedimentary characteristics of alluvial fan controlled by paleo gully geomorphology are more complicated,making it difficult to conduct the study of sedimentary characteristics with existing model.Guided by the research results of the modern Baiyanghe alluvial fan and combined with seismic,core,well logging,physical properties,oil-bearing characteristics and other data,the fluvial alluvial fan controlled by paleo gully geomorphology in Shawan Formation,Chunguang Oilfield was systematically studied in terms of palaeogeomorphology,lithofacies characteristics,microfacies distribution and other sedimentary characteristics,and a dynamic sedimentary evolution model was established.The results of the study show that this area was featured by two-channel paleo gully geomorphology,and the formation went through the filling process of gully-filling-progradation-retrogradation,with unbalanced deposition.Limited by the regional location,sedimentary subfacies were developed only at the middle and rear of the fan.The early stage was a flood period,and the fan was dominated by sedimentation.Controlled by the paleo gully geomorphology,the restricted channelized fan deposits were also developed.From the middle to the end of the fan,gravity current deposition was converted to traction current deposition.The late stage was a flood regression period,and with the filling and consolidation of the strata,the unrestricted fan deposits were developed and dominated by sheet flow deposit.On the basis of fine identification of sedimentary microfacies,the classification and evaluation criteria for reservoirs were established,the study results were applied to the northwest of Chunguang Oilfield,and three favorable areas were selected,and new wells were deployed to achieve breakthrough in the paleo-gully alluvial fan reservoirs.The study results have deepened the understanding of sedimentary evolution characteristics of alluvial fans controlled by different landforms and have important significance

关 键 词：古冲沟 辫状河型冲积扇 沉积特征 有利储层 春光油田 准噶尔盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]