Study On Distribution Of Remaining Oil And Development Plan In Chang4+5Formation Of Nanliangxi Region

The paper is depended on the theory of reservoir description, based on the integral comprehension of reservoir character, by dynamic analysis、reservoir engineering proof、 numerical simulation for the main method, unite dynamic and static state, analyze the contradictory of development、the movement regulation of oil/water, research the pattern of remaining oil in chang4+5of Nanliangxi region, propose the development plan of increase and table production. Finally, forecast those plans with technology of numerical simulation forecast.Some of the main results:1Chang4+5formation of Nanliangxi block can be divided into5substratum, according to the cyclic deposition. West monocline as background,4twigs nosing structures were developed in region. The chang4+5pertain to delta front depositional system, underwater distributary channel is developed more well in chang4+51.Chang4+5reservoir belong to low-porosity and super low permeable reservoir.2The whole water content ratio is in a lower level,but plan of water content ratio is in equable, because of the unequal of physical property and initial water saturation, such as Sw in the north part of block is much higher than that in the south part. Water breakthrough trend is mainly NE80°, parallel to the trend of major stress. Although taken synchronically water flooding, the individual well production rate is slip down, The individual well production rate is intimately related to reservoir properties and reservoir pressure.3The inverted nine spot diamond shaped flooding pattern is the best pattern shape in region of interest. Reasonable drawdown pressure is8.8MPa. Reasonable water intake per unit thickness is about0.64～0.96m3/m.d by proof. Water drive recovery efficiency is demarcated17.61%. Reasonable well spacing density is13.58wells/km2, nowadays the well spacing density is10.845wells/km2,so region of interest can be drived infill wells.4The influences of distribution of remaining oil include7aspects:①Because of well patterns;②Because of fractures;③The fringe of channel sand body;④High regions heterogeneity;⑤Because of interlayer interference;⑥Essential reservoir and non-essential reservoir;⑦Because of cyclothymiacs sedimentation.5Various development programs are formulated and predicted for the contradictions encountered in production and remaining oil distribution, such as diff exploitation degree、diff water intake per unit thickness、cyclic waterflooding、perforations adding and regulation of well network. Prediction results show that an appropriate exploitation degree and water injection rate can improve oil recovery. Perforations adding at main layer can improve the remaining oil extract.