二连低渗透油藏采油过程中储层伤害研究

探讨了二连地区低渗透的阿南、哈南两油田储层在注水开发过程中采到的伤害。由两油藏地质和油藏特征及7年（1990－1996）高注采比、高注水压力条件下采液指数和采油指数的变化,得出两油藏的伤害主要是应力敏感和有机结垢并作了详细分析论证。室内岩心围压－孔隙度、围压－渗透率关系数据证实了两油藏储层的强应力敏感性。从原油中石蜡、胶质沥青质存在状态及对原油组成变化和外界条件变化的感受性得出了两油田储层有机结垢的必然性。10年（1988－1998）来两油田采原油初馏点、石蜡和胶质沥青质含量上升（生产数据）,岩心孔隙压力下降时油相渗透率下降幅度大、孔隙压力不变时油相渗透率下降幅度小（岩心实验数据）,采用原油含水量低时（0％－30％）蜡沉演加快,1995－1998年针对有机结垢采取的92井次、9种解堵方法中复合解堵法效率最高,井底管柱附着物中石蜡含量高而无机盐少,均说明有机结垢是两油藏伤害的另一主要因素。两油藏储层均属弱速敏性。     

SB—4型高温调剖剂在稠油开采中的应用

用价廉易得的腐殖酸，交联剂，调节剂，增强剂研制成功了无毒，耐高温、堵塞强度高的ＳＢ－４型高温调剖剂，１９９３．７－１９９５．６在克拉玛依油田３个稠油区块的注蒸汽井和蒸汽吞吐井进行了１２井次调剖作业、改善了吸汽剖面、在有效期内取得了增油减水的效果，投入产出比达：１１．４，本文报道了该剂的基本配方，主要配方因素对调剖剂性能的影响及现场试验结果。     

胜利油田聚合物驱作法及效果

“九五”期间胜利油田在聚合物驱方面主要进行了以下六项工作。（1）深化聚合物驱油机理生影响因素研究;（2）严格控制聚合物产品的质量;（3）对特高含水油藏进行再认识,加强注聚区的选取和方案编制工作;（4）加大聚合物驱前的油藏准备工作;（50针对过程中出现的问题,强化注聚过程中的调整;（6）加强后续水驱单元的管理,在扩场取得了显著的降水增油效果和明显的经济效益。     

一种研究和评价复合化学驱采出液破乳剂的方法

比较了一种常规破乳剂与一种专门研制的复合驱破乳剂在模拟化学复合驱条件下的动态界面张力、运用Gibbs公式求出每种乳破剂在油水界面的吸附量以及每个破乳剂分子在界面所占的平均面积,从而研究破乳剂分子在没水界面的吸附对界膜稳定性的影响。初步发现,易于在油水界面吸附的乳剂由于形成的界面膜稳定性差,使得乳状液易于破乳。这为破乳剂的研制与筛选提供了一种方法。     

塔河油田缝洞型油藏不同反射特征技术研究

利用地震时间偏移剖面及现今构造资料,系统总结了塔河油田缝洞储集体在时间偏移剖面上的地震反射特征类型,对不同的反射特征进行了分类评价研究,同时建立了缝洞型储层地震反射模式量化识别分类标准,利用计算机识别技术对储集体的地震反射模式进行量化扫描,提高了缝洞储集体的预测精度和井位部署效率,降低了开发钻井的风险,提高了油井建产率,实现了碳酸盐岩缝洞型油藏的高效开发。     

松辽盆地三肇地区宋芳屯油田扶余油层成岩作用对储层的影响

用常规偏光显微镜、阴极发光显微镜、常规物性、粒度分析、压汞分析、扫描电镜、X射线衍射对宋芳屯油田扶余油层储集岩的成岩作用进行了综合研究。储集岩主要为高泥岩岩屑含量的细-极细粒长石岩屑砂岩。储集空间主要为缩小的原生粒间孔,具有低孔、低渗,变化大的排驱压力、孔喉半径和最大进汞饱和度,低的退出效率特征。对储层起破坏性的成岩作用主要有压实作用、胶结作用,起建设性的成岩作用主要是溶蚀作用。高的地温梯度、细的碎屑粒度和高的泥岩岩屑含量是压实作用下沉积物(岩)孔隙大大降低的关键因素。方解石的胶结作用是次于压实作用对储层起重要的破坏作用。长石和中基性火山岩岩屑的溶蚀对储层是重要的建设性作用。成岩作用早期的少量碳酸盐胶结物,可以抵抗压实作用;成岩作用早期沉淀的微晶石英、绿泥石包壳均有利于抵抗石英加大,两者均使得孔隙在一定程度上得以保存。     

Regulated rivers in the United Kingdom

This paper identifies the principal regulated rivers in Britain and summarizes their physical and ecological characteristics. Virtually all major rivers in the United Kingdom are shown to be regulated directly or indirectly by mainstream impoundments, interbasin transfers, pumped storage reservoirs, or groundwater abstractions. Flow records for sixty per cent of all gauging stations are significantly affected by flow manipulations. Three phases in the development of river regulation are identified: firstly, the development of direct supply and compensation reservoirs from 1840; secondly, the development of large dams and large-scale interbasin water transfers from 1890; and thirdly, the modern era of multipurpose river regulation that began in 1965. Any assessment of the environmental effects of river regulation must consider the spatial variation of natural river systems throughout the U.K., climatic changes, and the cumulative effect of river regulation and other impacts over an historic timescale. Today, the rivers of the U.K. are shown to have an underlying character that reflects the marked climatic, geologic, and topographic differences between the upland north and west, and lowland south and east; differences in part that relate to their different histories during the Pleistocene. However, many rivers show the effects of human impacts that began about 5000 years ago. Most rivers have experienced changes since about 1930 consequent upon afforestaton, land drainage, and channelization. These, together with short-term climatic changes, make defining ecological impacts of river regulation problematic. Pollution has had the most dramatic effects. Nevertheless, it is suggested that new concepts of environmentally sound river regulation could lead to the restoration and even enhancement of rivers in the United Kingdom.     

Three-Dimensional Modeling for Estimation of Hydraulic Retention Time in a Reservoir

A three-dimensional computational fluid dynamics model is used to estimate the hydraulic residence time for a portion of the Wachusett Reservoir in central Massachusetts. The basin under consideration has several major inflows and exhibits complex flow patterns. The basin is modeled using the FLUENT software package with particles used to track travel time in a steady-state flow field. A tetrahedral mesh with over 1.6 million cells is used with accurate depiction of basin bathymetry and inlet and outlet geometries. Modeling is performed to simulate behavior during a period when conditions are isothermal. It is determined that mean hydraulic residence time is 3–4?days; approximately half of what would be expected assuming strictly plug flow. The presence of a primary flow path, large scale eddies and stagnation zones contribute to the faster travel times. Reductions in inflow rates produce increased residence times and significant changes in flow patterns.     

Application of Watershed-Based Tank System Model for Rainwater Harvesting and Irrigation in India

The SOFTANK model optimally designs the watershed-based tank system by simulating field, tank, and groundwater balances. We applied this model to a small watershed consisting of six tanks (small reservoirs) in the semiarid region of India. We evaluated the existing tank system in this watershed and compared it to a one-tank system. Results showed that one tank at the outlet of the watershed would have been more beneficial [with benefit-cost (BC) ratio of 1.80] than the existing six-tank system (with BC ratio of 1.71). Finally, we performed the analysis for obtaining the optimal tank system for the watershed, and we found that the tanks for irrigation purposes are not economical for the small watershed. The groundwater source was enough for irrigation, so any additional investment in the tanks would be uneconomical. The results demonstrate the importance of the watershed-based tank system approach to design.     

Modeling a Plunging Underflow

A coupled three-dimensional hydrodynamics and two-dimensional underflow model is adapted to provide simulation of plunging inflows in reservoirs. The new approach accounts for the effect of the barotropic term prior to the plunge point of the inflow. Simulations of plunging flows in constant width and constant slope channels are conducted and the resulting plunge depths are in agreement with prior empirical models. Simulation of a previously measured underflow in Wellington Reservoir (Australia) demonstrates the model application to a plunging inflow in a natural water body and good agreement between field and model results.