Study On Physical Characteristics And Adjustment Methods In Delta Front Facies Reservoirs

Most main oilfields in China belong to continental river-delta deposit reservoirs, such as Lamadian,Sartu and Xingshugang fields in Daqing. These oilfields have been produced in high water-cut stage already, especially the main layers, which are mainly in fluvial facies growth; the total water-cut is up to 90%. Since there's inlayer heterogeneity in layered sandstone reservoirs and remaining oil potentials are mainly in thin or poor layers, which are mostly in delta front facies growth, this paper studies physical characteristics parameters interpretation methods for delta front deposit reservoirs to deepen the acknowledge to the depositional modes and features for further implementing the develop adjustment potentials and optimizing the potential tapping adjustment patterns. This practice has an important guiding sense to enhance the ultimate production recovery for mature oilfields.Gaotaizi reservoir is one of main reservoirs and main reserve constitute in Daqing oilfield. Gaotaizi reservoir in Nanâ…¡,â…¢zones in Sartu field have been produced in high water-cut stage, which are mainly in delta outer-front facies growth, and the production declining rate is faster in recent years. So this paper selects Gaotaizi reservoir in Nanâ…¡,â…¢zones to make studies on physical characteristics.During this research, delta outer-front facies sedimentary reservoirs have exposed such realities as follows: pore texture is complex, the correlativity between porosity and permeability is poor, and traditional mathematical statistics methods are not suitable for physical property prediction of this kind of reservoirs. This paper establishes the quantitative relations between pore texture characteristics and porosity,permeability and saturation, and builds the relational model between logs parameters and porosity,permeability and saturation by applying high-precision micro-digital image quantitative analysis technology. At the same time, this paper adopts sequential parameter method to establish porosity,permeability and water-saturation interpretation models by theoretical analysis under DLS, which is been widely used oilfields. By applying log vector inversion technology, pressure coring data and logs, this paper analysis the depositional setting,environments and characteristics under detailed geologic dissection; Combining with in-house laboratory analysis on the reservoir quality and development rules, this paper studies reservoir producing status by using dynamic and static data and numerical simulation method; It also studies the develop adjustment patterns on the basis of implementing in-site experiments of infill adjustments correspondingly. All the practices have improved the development effects, and have important guiding senses of tapping adjustment potentials in this reservoir in the future.