雁107砾岩油藏储集类型及对注水开发的影响

雁107厚层砾岩油藏的储层岩性以白云岩为主,在开发初期,立足于储集空间以孔隙为主的认识,按照一般砂砾岩油藏的开发模式制定了开发方案,在投入开发不到两年、采出程度不到5%的情况下,其产油量即从投产初期的150t/d左右下降至20t/d左右,综合含水高达80%。在没有岩芯资料和测井系列不适合于裂缝研究的条件下,从油藏开发中暴露的矛盾分析入手,借助井壁取芯、压力恢复测试等资料,重点讨论了储层岩性差别与储集类型的关系,以及储集类型的识别在雁107砾岩油藏开发中的重要意义。     

砂砾岩储层孔隙结构复杂模态差异机制

针对砂砾岩储层孔隙结构复杂、模态成因机制不明的情况，以325块岩芯分析化验数据为基础，利用压汞、铸体薄片、扫描电镜及X射线-CT扫描等方法，开展了岩石相分类、孔隙结构模态和驱油效率差异机制的研究，从油田开发与实用相结合的方式考虑，将砂砾岩储层岩相分为3大类、7亚类、13细类。研究表明：不同孔隙结构模态特征及注水驱替效率差异较大。单模态岩石颗粒以粗砂岩为主，孔隙发育程度高，孔隙呈网络状结构，相互连通性较好，注水驱替模式以网络状连通驱替为主，效率较高。双模态岩石颗粒由砾岩和中-粗砂岩两级颗粒组成，孔隙较发育，孔隙呈疏网状结构，相互连通性一般，注水驱替模式以星点状连通驱替为主，效率一般。复模态岩石颗粒由砾石、中-粗砂岩、粉砂或泥质三级颗粒组成，孔隙发育一般，孔隙呈星点状结构，相互连通较差，注水驱替模式以零星散乱状驱替为主，局部存在高渗带，效率整体较差。相同岩相呈不同孔隙结构模态和不同的岩相呈相同的结构模态的情况普遍存在。颗粒排列方式及成岩作用差异改造导致了同相异态，而颗粒分选、磨圆、排列方式等因素形成了异相同态。     

成都平原的晚新生代构造

根据成都平原晚新生代地层的展布、接触关系,以及与邻区的构造组合,对成都平原的基本构造格架进行了初步分析,描述了蒲江-新津断裂、大邑断裂、竹瓦铺断裂、绵竹断裂等晚新生代断裂,将成都平原的构造演化划分为6个阶段,对上述断裂的构造活动性与龙门山断裂带进行了分析对比.     

近岸水下扇砂砾岩体的储集性研究以胜利油区沾化凹陷埕913-埕916井区沙三段为例

以胜利油区沾化凹陷北部埕913-埕916井区沙河街组三段为研究对象,详细论述了近岸水下扇砂砾岩体的储集空间类型、特征;并深入讨论了近岸水下扇沉积不同微相内砂砾岩的物性特征,结果表明近岸水下扇扇中分支水道与扇中前缘微相内的砂砾岩体的储集性最好.     

云南陇川盆地东南缘新第三系砾岩成因及沉积模型

云南陇川盆地东南缘新第三系南林组砾岩沉积物由扇根碎屑流、扇中河道和扇缘水道及沼泽沉积构成，文章探讨了各类砾岩的成因、粒度分布，指出该区的砾岩沉积模型及其油气勘探意义。     

基于恒速压汞技术的砂砾岩复模态特征表征

针对砂砾岩储层砾石、砂级颗粒和粘土级颗粒混杂堆积的复模态结构导致的复杂孔喉分布,应用恒速压汞技术假设多孔介质由孔径大小不同的孔隙和吼道构成的理论模型优势以区分孔隙和吼道的大小分布,对新疆百口泉油田百口泉组砂砾岩储层进行了直观、定量的测试分析。结果表明:(1)砂砾岩储层孔隙分布多呈单峰态,孔隙半径分布范围为53~559μm,平均214μm,砂砾岩储层喉道分布呈宽缓的多峰态,且主峰值喉道半径偏小(5μm),喉道半径分布范围为1~29μm,平均为8μm,孔喉比亦表现为多峰态的分布特征,分布范围为5~295,平均46,砂砾岩储层喉道的极强非均质性是导致其储层微观结构复杂的决定性因素;(2)根据压汞曲线形态及不同孔径单元进汞曲线关系将其分为3类并对应研究区3种储层类型。第一类初期孔隙及喉道进汞一致且缓慢上升,后期发生不同程度的上翘,指示了该类储层孔喉比小,连通性好的特征,为较优质的储层。第二类初期表现为喉道进汞曲线大幅升高与孔隙进汞曲线分离,后期缓慢升高的特征,反映了该类储层喉道发育较差,孔隙发育尚可,整体为储集性能较好但渗流性能较差的特征。第三类压汞曲线表现为孔隙及喉道的进汞压力快速大幅升高趋势,指示了孔隙及喉道均不太发育且连通性较差的特征,为较差的储层类型。     

埕南断裂带913区块沙河街组三段砂砾岩体成藏条件分析

埕南断裂带埕 913区块是济阳坳陷埕南断裂带目前已发现的沙河街组三段砂砾岩体中唯一含油气区块。生、储、盖、圈闭条件的分析结果表明 ,虽然古隆起构造背景为其提供了油气汇聚指向、相对的浅埋藏所对应的良好储集性能、发育多种圈闭等成藏必要或有利条件 ,但有别于其他区块的特殊条件是该砂砾岩体之上发育有泥岩盖层或内部发育泥岩隔层。断层面封堵与否是成藏最关键的因素 ,断层面封堵的基本条件是要求砂砾岩体之上有泥岩盖层或隔层 ,具泥岩盖层或隔层的砂砾岩体与断鼻、断块圈闭匹配方可形成构造 -岩性油气藏。     

准噶尔盆地西北缘砾岩油藏广义水驱图版建立及应用

标准的童氏图版已经被广泛应用于中高渗透率砂岩水驱油田的可采储量预测和采收率标定,以及水驱开发中后期含水率预测,但是对于具有复模态孔隙特征和严重非均质性的砾岩油藏适应性较差。根据准噶尔盆地西北缘71个砾岩区块实际生产动态数据,使用数理统计学方法,把经验系数7.5修正为8.65,引入水油比修正系数c,并建立砾岩油藏广义水驱图版。经过实例分析,证明砾岩油藏广义水驱图版对于百口泉油田砾岩区块适应性较好,并且对于整个西北缘砾岩油藏水驱开发具有指导意义。     

K-Ar dating of late Mesozoic volcanism and geochemistry of volcanic gravels in the North Huaiyang Belt, Dabie orogen: Constraints on the stratigraphic framework and exhumation of the northern Dabie orthogneiss complex

Two eruption episodes are identified through systematic field investigations and K-Ar dating of the lateMesozoic volcanic rocks in the North Huaiyang belt (NHB),Dabie orogenic belt, of which the earlier volcanic suitetermed Maotanchang Fm. (Fm.) occurring at Jinzhai,Xianhualing and Maotanchang, etc., was erupted from 149Ma to 138 Ma. The other named Xiaotian Fm. mainly dis-tributed at Xiaotian, Shucheng, etc., was formed between132 Ma and 116 Ma. During the eruption gap of the two vol-canic suites deposited a volcano-sedimentary conglomeratelayer, which are composed of the multi-compositional gravels, including the North Dabie orthogneiss complex (NDOC),volcanic gravels, etc. These volcanic gravels in the con-glomerate layer show identical geochemical and isotopic compositions (87Sr/86Sr(t) =0.7084-0.7092, (Nd (t) = 21.8-24.4) to the Maotanchang Fm. volcanic rocks (87Sr/86Sr = 0.7086-0.7102, (Nd = 19.2-24.4), but significantly distinct from those of Xiaotian Fm. (87Sr/86Sr = 0.7076-0.7084, (Nd = 17.2 - 19.2). K-Ar dating results of its underlying andoverlying volcanic sequences indicate that the conglomerate layers were deposite d at ~135 Ma. This suggests that the NDOC was rapidly exhumed to the surface dur ing or shortly before ~135 Ma and became the important provenance of the late Me sozoic volcano-sedimentary basins in the NHB. In combination with the regional v olcano-sedimentary correlation, we divided the Mesozoic stratigraphic sequence i n the NHB from base to top into Fanghushan Fm. (>160 Ma), Yuantongshan Fm. (/mid dle- lower segment of Sanjianpu Fm.) (160-149 Ma), Maotanchang Fm. (/Zhougongsh an Fm./upper segment of Sanjianpu Fm./Fenghuangtai Fm.) (149-135 Ma) and Xiaoti an Fm. (/Baidafan Fm./Heshidu Fm.) (135-116 Ma).     

Sedimentary environment of the Dajin conglomerate in Tibet, age of foraminiferan assemblages and their tectonic significance

The Dajin conglomerate, which is one of the most important sedimentary successions of the Xigaze forearc basin in Tibet, China, consists of deep-shallow marine tuffaceous turbidites and clastic rocks bearing Nummulites, Assilina, Alveolina and Lockhartia. These fossils are very similar to the foraminiferan in the Jialazi and Maila conglomerates, and those in Gangba and Dingri areas. They developed in the Eocene. By analyzing the spatial variation of Eocene sedimentary environments of Tibet Plateau and the foraminiferan in the Dajin conglomerate, we found that Eocene sedimentation should take place on both sides of the Yarlung Tsangpo suture, and the late Eocene tectonic uplifting should make the forearc basin expose out of the sea level and begin to receive nonmarine deposits.