Study On North-Ⅱ-West Developmental Effect Evaluation And Technical And Economic Limits For The Adjustment Of The Well Pattern In The Layer System

North-Ⅱ-West block is located in the northern part of Changyuan oilfield, Saertu oilfield, Daqing oilfield, north of the West Wing, After years of development, had gone through the basic well pattern, water flooding well network and encryption, encryption for the second time, third infill wells.At present, the comprehensive water content of the block has reached more than 90%,therefore,this paper analyzes the North Saertu Development Area North-Ⅱ-West yield, water content, water cut, production decline rate, changes of development index and the degree of overall development and effect evaluation; through numerical simulation, coring well, dynamic monitoring data of the comprehensive analysis of the reservoir producing degree, quantify the remaining oil potential distribution; combination of permeability and thickness combination, combination length, and the reasonable well pattern, well spacing on the development effect influence to determine the layer to the restructuring of the Department of technical limits.Have achieved 3 aspects of understanding:North-Ⅱ-West block encryption layer has characteristics of well pattern and layer, mining of complex objects and layers cross each other, reservoir classification mining contradiction more prominent and complex layer pattern make delicate adjustment of extra high water cut period targeted not strong. At present, the comprehensive water content of the North-Ⅱ-West reaches 92.35%, the yield obeys the exponential decline, and the decline is relatively fast. It needs to carry out the structural adjustment of the layer system to improve oil production.The remaining oil in North-Ⅱ-West basically has the following kinds,(1)Remaining oil exists in plane thin difference position;(2)Remaining oil exists in the vertical thin layer;(3)Remaining oil exists in the well pattern imperfect place;(4)Remaining oil exists in phase band boundary;(5)Remaining oil exists in shunt type(retention area)place.The whole recovery percent of reserves in North-Ⅱ-West is not high and remaining oil has great potential. But the possibility of structural adjustment through the water injection is small. The reorganization of the Department of permeability layer should be controlled below 4.North-ⅱ-West production wells span should be controlled below 130 m. Recommend the use of 5 sets of well pattern mining, Sartu based ranks well, Sartu secondary encryption 250 m transverse linear pattern, Portuguese Ⅱ a encryption layer 250 m transverse linear pattern, high I1-13 layer 175 m five point method of well pattern, high I14 ~ ⅡI high strata drilled a set of independent 125 m five point well. The experimental block in this well pattern would be research using numerical simulation. The finally recovery would be enhanced about 3.65 point. The economic benefit would be increased 1.59334 billion yuan.