Study On The Rule Of Water In D - Zone Reservoir And Its Countermeasures

Xifeng oilfield located in Qingyang city, Gansu province, D area is located in the south of Xifeng oilfield, and it’s structure locates in the southwest of northern Shaanxi slope, which is a wide and gentle monoclinal structure of low permeability lithologic reservoir. Because of it’s poor physical properties and natural fracture development, which cause the water-cut of partial wells runs high and low degree of partial response, that makes it difficult for the reservoir to keep a steady production. This thesis aimed at D area reservoir geological characteristics and the problems existing in the development, studied this problem mainly from following aspects and obtained the corresponding results:(1) Applied all kinds of static geological data, etc, using sedimentology and petroleum geology theory and method, studied Structure, sedimentary facies, reservoir distribution and flow distribution of D area reservoir, in order to provide a geological basis for Analysising the Water breakthought rules.(2) Based on seepage features of anisotropic reservoir, studied the maximum injection-production well spacing were calculated, determined the premise conditions for water breakthrough rule.(3) Using the seepage theory, reservoir engineering method, studied reserves producing degree,water breakthrough time and law of water cut rise after water breakthrough of D low permeability reservoir with the waterflooding way, which considered the influence factor of start-up pressure gradient,natural fracture and vertical heterogeneity.(4) By using numerical simulation method, carride out quantitative study on start-up pressure gradient, Permeability anisotropy, fracture size and Fracture permeability, water injection intensity and vertical heterogeneity affect the law of water cut rising, in order to provide theoretical basis for the next step discriminant of water breakthrough reason(5) Using the statistical method, classified the different well of water breakthrough, Integrated geology, reservoir engineering and numerical simulation results, summarized the Water breakthought type and Water breakthought rule of the oil well in the actual oil field.(6) Combined with reservoir geological characteristics, the water breakthrough research results and the early stage of the oil wells modification measures effect, evaluated the suitability of existing technology, put forward adjusting technology and the suggestion to improve the effect of oilfield development.