Visualization of the Effect of Porous Media Wettability on Polymer Flooding Performance through Unconsolidated Porous Media using Magnetic Resonance Imaging

Abstract

Waterflooding effectiveness depends on the mobility ratio of the injected water to displaced fluids, and on the geologic heterogeneity of the reservoir rock. Rock wettability also affects the performance of water and polymer flooding. It is generally recognized that waterflooding in a water-wet reservoir is more efficient than waterflooding in an oil-wet reservoir. Polymer absorption/retention in porous media is also affected by rock wettability. The Centric Scan SPRITE Magnetic Resonance Imaging (MRI) technique is applied in this work to visualize the performance of polymerflooding and to quantify in situ fluid saturation distribution in rocks with wettability ranging from strongly water-wet to preferentially oil-wet.     

表面活性剂对低渗油湿灰岩表面性质及渗吸行为的影响

裂缝发育的低渗灰岩储层，当基质岩块为混湿及油湿时，毛细渗吸驱油作用很弱。本工作采用毛管上升、渗吸及相对渗透率曲线方法，在62℃下研究了CTAB和SDBS溶液对油湿灰岩表面性质及渗吸行为的影响。浓度为700mg／L时，SDBS溶液与原油间的界面张力为0．035mN／m，而CTAB溶液为1．25mN／m；随着浓度增大，SDBS溶液使亲油的毛管表面润湿接触角缓慢减小，而CTAB溶液使润湿接触角大幅减小，在与最大吸附量对应的浓度下润湿接触角有最低值；亲油岩心在CTAB溶液中的渗吸驱油速度较SDBS溶液中的渗吸驱油速度高；相渗曲线表明，与亲油岩心／SDBS溶液体系相比，亲油岩心／CTAB溶液体系的油相相对渗透率较高而水相相对渗透率较低。因此，CTAB类阳离子表面活性剂可望用于该类油藏的开发。讨论了相关的机理。图6参10。     

Investigating the performance of hot water injection in geostatistically generated permeable media

The study investigates the performance of hot water flooding compared to conventional water flooding in recovering heavy oil from heterogeneous reservoirs through fine-mesh numerical simulations. A total of 16 permeability maps were generated geostatistically to cover a wide range of reservoir heterogeneity. Two measures of heterogeneity were used to characterize the permeability maps: the Dykstra–Parsons coefficient and the spatial correlation length. Extensive three-dimensional, fine-mesh simulation runs were performed to study the functional relationships between several design parameters and the oil recovery obtained during hot water flooding. These results were then compared to those obtained by conventional water flooding. Parameters which were investigated include: (1) degree of reservoir heterogeneity (2) injected fluid temperature (3) well configurations, and (4) viscosity ratio. Results showed that these parameters play important roles in the displacement behavior of heavy oil, with reservoir heterogeneity having more significant effects. It is proven that hot water flooding can be more effective than conventional one by considering the critical values of the above studied parameters. The paper also shows the conditions that can be detrimental to hot water flooding.     

新型声波探头的研制与应用

针对目前常用的声波换能器存在测试不方便,横波首波位置难以确定且不能模拟地层条件等问题,研制了新型声波探头。新型探头将纵横波晶片合为一体,并且互不影响,能有效抑制纵波干扰,可以明确判断出横波的首波位置。该声波探头中间的不锈钢引流管线可以改变岩心孔隙流体性质和孔隙压力。将声波探头安装在岩心夹持器中,就可在高温(150℃)高压(90MPa)下模拟地层条件的同时获取岩心的纵横波波形,读出纵横波时差,进而算出所测岩心的纵横波速度。新型声波探头具有结构简单、精确度高等优点,可用于岩心力学参数分析以及流体识别等领域。     

Reservoir characterization utilizing core and wire line logging data for Kareem sandstone,Ashrafi oil Field,Gulf of Suez,Egypt

This study aims to integrate core and wire line logging data for evaluation of Kareem sandstone (Middle Miocene) in Ashrafi Field, Gulf of Suez, Egypt. The study has been carried out on seven wells ASHRAFI_A_01_ST, ASHRAFI_A_02_ST, ASHRAFI_H_IX_ST2, ASHRAFI_I_1X_ST, ASHRAFI_K_1X, ASHRAFI_SW_04, ASHRAFI_SW_06, by using wire line logging data and core data. The interpretation of these data has been done by using Interactive Petrophysics software.The Net pay thickness ranges between 17?ft to about 110?ft, porosity varies from 13% to 26%, permeability from 125?mD to about 960?mD, water saturation from 19% to about 50% and shale content from about 18% to about 56%. The interpretation of the Kareem sandstone (core data for ASHRAFI_SW_04 well) indicates that the average core porosity value is about 17% and the average core permeability is about 800?mD, which indicate a suitable reservoir. The porosity increases with the increasing of the permeability and the relationship between them has good correlation coefficient of 0.81 for wire line logging data set and 0.85 for core data set. These relations can be used to determine permeability from porosity for sandstone of Kareem Formation.The new development area for Ashrafi Field can be determined where there are two zones: one in the Middle and the other in South west. Stratigraphic correlation chart shows that, the Kareem Formation thickness varies laterally in Ashrafi field so, the new well location could be determined perfectly. The integration between well logging data and core data are very important tools to evaluate the degree of heterogeneity in the Kareem sandstone and storage capacity properties as well as the zone of interest of productivity and perforation.