四川盆地中西部上三叠统砂岩非构造裂缝储层

四川盆地中西部上三叠统砂岩的裂缝控制了流体的储集与渗滤能力。裂缝为非构造作用成因,由差异压实作用、溶蚀作用、岩溶陷落作用及重力滑动作用形成。古残丘的高部位和较高部位是非构造裂缝网系最发育的地方,也是布置探井和开发井的理想位置。     

中东地区孔洞型碳酸盐岩油藏非线性渗流机理

中东地区部分碳酸盐岩储层类型以孔洞型为主,裂缝不发育,具有高孔低渗的特征,与中国塔河油田缝洞型碳酸盐岩存在较大差异。为了提高对孔洞型碳酸盐岩油藏低速渗流规律的认识,通过对伊拉克HFY油田碳酸盐岩岩样开展单相油、单相水渗流实验和岩心压汞实验,分析基质型碳酸盐岩与孔洞型碳酸盐岩的低速非线性渗流特征。实验结果表明:孔洞型碳酸盐岩具有低速非线性渗流特征且与常规低渗砂岩不同,拟启动压力梯度与渗透率不存在线性关系。同时,由于孔洞型碳酸盐岩渗流孔道半径的多极化,导致其渗流通道在低速渗流区间存在逐级启动的现象,得出孔洞型碳酸盐岩存在拟启动压力梯度,但不存在真实启动压力梯度,并提出孔道全流动压力梯度的观念。所得实验结果对正确认识孔洞型碳酸盐岩低速渗流机理以及合理开发碳酸盐岩油藏提供了技术支撑。     

RESERVOIR POTENTIAL OF A LACUSTRINE MIXED CARBONATE / SILICICLASTIC GAS RESERVOIR: THE LOWER TRIASSIC ROGENSTEIN IN THE NETHERLANDS

The Lower Triassic Rogenstein Member of the Buntsandstein Formation produces gas at the De Wijk and Wanneperveen fields, NE Netherlands and consists mainly of claystones with intercalated oolitic limestone beds. The excellent reservoir properties of the oolites (φ= 20‐30%; k = 5‐4000 mD) are predominantly controlled by depositional facies. Oolitic limestones are interpreted as the storm and wave deposits of a shallow, desert lake located in the Central European Buntsandstein Basin. The vertical sequence of lithofacies in the Rogenstein Member indicates cyclic changes of relative lake level. The reservoir rock is vertically arranged in a three‐fold hierarchy of cycles, recognised both in cores and wireline logs. These cycles are a key to understanding the distribution of reservoir facies, and are used as the basis for a high‐resolution sequence stratigraphic correlation of the reservoir units. Slight regional‐scale thickness variations of the Rogenstein Member (in the order of tens of metres) are interpreted as the effects of differential subsidence associated with the inherited Palaeozoic structural framework. The depositional basin can be subdivided into subtle palaeo‐highs and ‐lows which controlled facies distribution during Rogenstein deposition. Oolitic limestones show their greatest lateral extent and thickest development in the Middle Rogenstein during large‐scale maximum flooding. Potential reservoir rocks (decimetre to metres thick) are present in the NE Netherlands, in particular in the Lauwerszee Trough and the Lower Saxony Basin, where abundant gas shows of 200 ‐ 4000 ppm CH₄ have been recorded. Preserved primary porosity is interpreted to be a result of rapid burial in subtle depositional palaeo‐lows in this area. The thickest, amalgamated oolite intervals (tens of metres thick) occur in the eastern part of the Central Netherlands Basin. Because of poor reservoir properties, other areas appear to be less promising in terms of Rogenstein exploration potential.     

贵州赤水地区中、下三叠统碳酸盐岩储层特征及分类评价

本文主要对贵州赤水地区中、下三叠雷口坡组、嘉陵江组碳酸盐岩储层特征进行研究.作者采用产能系数法,确定其储层的下限,然后综合岩石学特征、物性特征、孔隙结构特征及储层下限,将本区储层分为4类.本区大部分瞩Ⅱ、Ⅲ类,为裂缝-孔隙型储层.     

成岩作用对致密砂岩储层物性的影响——以川中地区上三叠统须四段气藏为例

川中地区上三叠统须家河组四段砂岩是四川盆地内的天然气储层之一，该碎屑岩储层具有低孔隙度、低渗透率的特点。在对该区上三叠统须家河组气藏宏观沉积特征研究的基础上, 采用岩石薄片、铸体薄片、扫描电镜及X射线衍射等方法, 对该气藏储层的成岩作用及其对储集物性的影响进行了探讨，建立了该区致密砂岩成岩作用序列以及孔隙演化模式。研究结论如下：①随压实作用的不断增强，孔隙度呈持续下降的趋势；②成岩作用对致密砂岩储集层的影响具有双重性，压实作用、胶结作用使得砂岩孔隙度降低，而溶蚀作用则增加了孔隙度；③该区的孔隙构成主要是环边绿泥石剩余原生粒间孔以及溶蚀形成的长石、岩屑粒内溶孔，泥质杂基溶蚀粒间孔，伊利石黏土中微孔以及由压实压裂、压实滑动和构造动力所形成的微裂缝孔；④勘探中既要注意机械压实作用、压溶作用对储层的负面影响，同时也要重视成岩早期环边绿泥石胶结物形成、碎屑（主要是长石）及其填隙物溶蚀作用等有利因素。     

中上扬子区古生界深水斜坡及台地边缘碳酸盐岩成岩作用

本文在岩石学研究的基础上,利用电子探针、碳氧同位素、包裹体古盐度分析、地球化学分析等测试资料,详细研究了中上扬子台地南北缘深水斜坡及台地边缘相碳酸盐岩成岩作用特征,如早期岩化作用、胶结作用、白云石化作用等。在此基础上对研究区深水斜坡相及台地边缘相碳酸盐岩所经历的成岩环境进行了划分,建立了该区深水斜坡相及台地边缘相碳酸盐岩的孔隙演化模式。      

任丘碳酸盐岩油藏的开发

任丘油田位于华北盆地冀中拗陷的中部,自1965年开始钻探,当时主要目的层是下第三系,至1972年仅在几口探井中获得少量油流,没有大的发现.此后加强了地球物理勘探工作,发现了第三系覆盖下的深部地质构造(图1),并部署了一些较深的探井.     

轮古西地区奥陶系碳酸盐岩储层特征研究

塔里木盆地轮古西地区奥陶系碳酸盐岩油气藏在很大程度上受岩溶型储层发育的控制，深入总结其储层特征及其控制因素，对油气勘探开发具有重要意义。为此从储层岩石学及储集性能等方面，对该区的奥陶系碳酸盐岩储层特征进行了阐述和分析，认为该区储层的基质孔渗极差，难以形成有利的储集空间，而次生孔隙（裂缝、溶蚀孔洞、洞穴等）构成了该区的主要储集空间，裂缝-孔洞型、洞穴型储集层较为发育，是最有勘探价值的储集层。通过对构造演化特征和岩溶系统的分析，认为储层的原生孔隙和沉积相带是次生孔隙形成的基础条件，构造运动产生的裂缝是促进岩溶发育、控制储集体发育的关键因素，岩溶作用是控制储层发育的主要因素。     

FLOW UNIT CHARACTERISATION IN THE PERMIAN‐TRIASSIC CARBONATE RESERVOIR SUCCESSION AT SOUTH PARS GASFIELD,OFFSHORE IRAN

The South Pars gasfield (offshore southern Iran) has been investigated in detail in recent studies in terms of depositional, diagenetic and reservoir properties of the Permian‐Triassic carbonate succession. In the present paper, a variety of flow unit approaches were applied to identify reservoir (flow) and non‐reservoir (baffle or barrier) units within the Permian‐Triassic carbonates. The zonation scheme was based on three approaches; (i) flow units were identified using the stratigraphic modified Lorenz plot (SMLP) method; (ii) hydraulic flow units were identified using a parameter known as the flow zone indicator (FZI); and (iii) petrophysical flow units (PFUs) were determined using the pore throat radius (R₃₅) and water saturation (S_w) parameters. Studies of flow units at both macro‐ and micro‐scales showed that flow properties were controlled by both depositional and diagenetic features. In order to construct a reservoir flow model, the flow units and PFUs were correlated between the four wells studied within a sequence stratigraphic framework. SMLP‐derived flow units appeared to be distributed homogenously within the reservoir succession resulting in a layer‐cake architecture. By contrast, the FZI‐derived hydraulic flow units drew attention to the presence of small‐scale heterogeneities within the reservoir. A comparison between these methods showed that the flow model derived from PFUs included greater vertical and horizontal heterogeneities, especially in the Upper Dalan Member (upper K4 reservoir unit). This was due to depositional/diagenetic heterogeneities in both lateral and vertical directions, and the parameters applied in the PFU method. The PFU‐derived flow model showed a closer relationship to the actual reservoir performance than the flow units derived by the other methods and can therefore be used as the basis for future dynamic flow simulation.     

地应力在千米桥潜山碳酸盐岩储层中的应用

碳酸盐岩储层是低孔低渗储层,裂缝相对发育,只有裂缝走向与地应力方向平行、成锐角(小于45°)或呈钝角(大于135°)时,其裂缝才有可能成为有效缝。同时,从油气运移机理上讲,地应力又控制油气富集情况。本文主要从这两方面阐述地应力在千米桥潜山碳酸盐岩储层中的应用。