The Study Of Residual Oil Distribution And Production Techniques Of Low Permeability Reservoirs In High Water-cut Stage Taking The Example Of Wendong ES3_M Reservoir

Nowadays, few examples of successful exploiting reservoirs with deep layer, low percolation, high temperature and high pressure, and very difficult development of them induce no existence of mature theory, technique and method. Base on the case of Wendong sanzhong reservoir, the reservoir description, reservoir dynamic analysis, reservoir engineering, numerical simulation and petroleum engineering are integrated applied. Based on the reservoir characteristics of wendong sanzhong reservoir, researched on fine flow unite contrast, structural interpretation combined with borehole seismic materials, sedimentary microfacies analysis, diagenesis of reservoir and fracture characteristics, studies of the heterogeneity and sensibility of reservoir, the fine geology model of oil reservoir is established. Through in-house tests, dynamic analysis and numerical simulation, the distribution of residual oil law is studied and the corresponding digging measures are proposed. Major researches of this paper include,1. The sedimentary microfacies are imported into the geology model. The major sedimentary characteristics of wendong sanzhong reservoir, gravity flow sediment of deep-deeper water environments, are clarified. In the gravity flow sediment, fan shaped and non-fan shaped turbidite facies, which are controlled by synsedimentary faults, are developed. In these turbidite facies, the main is axial trend gravity sediment. There are four kinds of sand body microfacies, deep channel, shallow channel, near overtopping and farther overtopping microfacies. The direction of channel is water drive predominance passage. The research of diagenesis indicates that this is epigenetic stage, which includes five kinds of diagenetic pattern. The best reservoir is solutional phase, the less is lithofacies that cemented by carbonate and enlarged secondarily by quartz and the worst is lapidofacies that cemented by anhydrite. Three types of different pore, large pore coarse throat structure, intermediate pore medium throat structure and fine pore fine throat structure, are divided. Fine and reliable reservoir geology model is established in this paper, which is the base of correct researches on the distribution of residual oil.2. According to the digging requirements, 55 flow blocks are divided and each flow block is sorted with the clustering method. In the 3 kinds of flow block that are sorted, there are 13 flow blocks in sort â… ,25 ones in sort â…¡ and 17 ones in sort â…¢.3. The accuracy of understanding reservoir structure is obviously improved. The structures of complicated structural belt of wen 13 east block and wen 13 west block are amended greatly. The facts verify that this is correct understanding of structure. Through stepout, there is the increase of 1.03 million ton of OOIP.4. The percolation mechanism of reservoirs with deep layer, super high pressure and low percolation are studied. The research results indicate, (1) Net burden pressure has negative relationship with reservoir characteristics. With the increase of burden pressure, the decrease of porosity, permeability, compacting factors and pore configuration coefficient. However, this is little decrease. (2) Applying microvisual model on the waterflood experiment of this reservoir indicates that the speed and the pressure of water injection have little effect on the formation of residual oil, while the heterogeneity of pore texture is the major cause of effecting flood efficiency. (3) The sensibility research indicates that wendong sanzhong reservoir is medium-high velocity sensibility, low water sensibility and low saline sensibility, and the velocity sensibility effects the development of reservoir greater than other factors.The achievements of this paper have been used in digging the residual oil in wendong sanzhong reservoir. The field implication indicates that, they are reliable, good applicable, maneuverable measures; in the same time they also bring excellent economic benefit. Meanwhile, the research method of oil residual distribution and digging techniques of reservoirs with deep layer, super high temperature and high-pressure are the guidance of development of the assemble reservoir.The achievements of this paper have been used in digging the residual oil in wendong sanzhong reservoir. The field implication indicates that, they are reliable, good applicable, maneuverable measures; in the same time they also bring excellent economic benefit. Meanwhile, the research method of oil residual distribution and digging techniques of reservoirs with deep layer, super high temperature and high-pressure are the guidance of development of the assemble reservoir.The achievements of this paper have been used in digging the residual oil in wendong sanzhong reservoir. The field implication indicates that, they are reliable, good applicable, maneuverable measures; in the same time they also bring excellent economic benefit. Meanwhile, the research method of oil residual distribution and digging techniques of reservoirs with deep layer, super high temperature and high-pressure are the guidance of development of the assemble reservoir.