Study On Characteristics Of Remaining Oil And Adjustment Of Well Pattern In South Seven Area Of Saertu Oil Field,Daqing

At present,Sanan Oilfield has entered high water cut development stage,most of a kind of reservoir has been carried out three times oil development,polymer flooding and water flooding yield decreased gradually increasing storage potential and smaller,stable production of crude oil potential mainly concentrated in the two or three types of reservoir mainly poor thin layer.Daqing seven District of Saertu oilfield basic well pattern developed in 1965 and1985,conducted an encryption adjustment,for the two time in 1996 two encryption adjustment,encryption adjustment after the block increase recoverable reserves,maintain a stable block,improve the use of thin and poor reservoir conditions,early better development effect.With the development of mining time,the rising rate of water cut in the two infill adjustment wells is speeding up,the production decline range is large,the pressure system is irrational,and the contradiction of water injection mode is becoming increasingly prominent.In 2000 two adjustment wells injection system adjust ment,injection production wells 11.The three encryption adjustment was carried out in 2002.In 2011 to further improve the effect of block development,improve the block recovery,combined with the actual development of the block,on the basis of the residual oil in the area causes and the distribution of remaining oil tapping countermea sure research,the injection production to adapt to the situation of poor wells continue to carry out the injection production system adjustment,the research results for the high water cut during the period of water flooding oilfield stable theoretical basis for breakthrough stage of high water cut reservoir remaining oil tapping has important practical significance and reference value.The research object of this article is Daqing Saertu oilfield in Southern southern area seven two times and three times of encryption encryption for the object to drilling,coring,logging,and other static data to establish the model based on the residual oil,water absorption liquid production profile and production logging for evaluating reservoir at present,in the dynamic data and casing status the single well potential study.Make full use of the numerical simulation method to evaluate the relationship between injection and production,deepen the understanding of the residual oil in the area,with the help of the previous research theories,methods and achievements,to build the Southern District seven remaining oil tapping framework,in this area the remaining oil distribution and potential tapping direction,the residual oil comprehensive evaluation block level.Through research,the following conclusions and recognition have be en obtained:No.1.Fine sedimentary framework has been set up by subdividing the Putaohua,Portugal and high I reservoirs in the main reservoir of South seven area into 110 sedimentary units.5 sedimentary types controlled by well pattern control in 7 major sedimentary types are studied.The sedimentary facies profile of the block is completed,which lays a foundation for further research.No.2.The mining area of the South seven area is mainly composed of 5 reservoirs,the total number is 108 layers.In small layer as the simulation model of the longitudinal unit,divided into 108 simulation unit,using Petrel software,the grid properties(porosity,permeability and effective thickness)of phase controlled interpolation,the result can reflect the change trend of formation,laid the foundation for the implement ation of the fine sedimentary body scope and the distribution of residual oil.No.3.Over the years,through the use of oil wells measures data and absorbing fluid profile data for repeated fitting,fitting the geological reserves of 28 million 914 thousand and 730 tons,the relative error is 0.28%,higher precision,and provide the basis for the feasibility of tapping remaining oil.No.4.The results of theoretical research: the distance is too large for injection wells,injection starting pressure is high,is not conducive to the low level of the thin and poor permeability reservoir,so make sure it is not encrypted in the adjustment situation,will block things to note the same net wells spacing is adjusted to 250 m,reduce the injection production well spacing for comprehensive utilization of 125 m two or three wells north-south direction,constitute the five spot pattern.No.5.Research shows that the plane stable thin body relative concentration of remaining oil distribution of delta sand,is the main object of the test area protuction;longitudinal residual oil accounted for the remaining oil distribution in block II group and III group SaSa in more than 60%.No.6.The study shows that the remaining oil types in this block are mainly oil production difference and injection production imperfect,which accounts for 32.38% of the remaining oil sandstone thickness and 42.50% of the effective,which is the main object of adjustment and tapping the potential of this block.No.7.The remaining oil formation origin: grape poor reservoir is mainly due to the vertical development of well long,contradiction between layers,the lower residual oil reservoirs and the formation of difference,there is also a part of imperfect injection production of remaining oil in the local area,due to poor reservoir;plane injection wells,injection production relationship is not perfect and the formation of remaining oil.No.8.The injection production relatioin through subdivision of layer water injection,fine water plugging and reperforating combination of perfect,thus making the non main oil reservoir has been improved,improve the control degree of water flooding and tapping potential of remaining oil effectively,improve the ultimate recovery,realize the sustainable development of oilfield.