Study On The Influencing Factors And Development Methods Of Viscosity Of Ordinary Heavy Oil In The Expanded Area Of Block A

The expanded area of Block A is located in the north of the transition zone,with an area of 10.33km²and geological reserves of 362.96×10⁴T.At present,the study area is in the preliminary exploitation stage,and there are some problems such as high crude oil viscosity and lack of exploitation experience.Therefore,in order to put forward a complete set of exploitation plan,it is necessary to analyze the variation law of crude oil viscosity and the distribution of remaining oil in the study area,and formulate a reasonable development plan according to the seepage characteristics and development theory of the study area,which is of far-reaching significance to the development of the study area.Firstly,Wells were selected according to the location distribution on the plane of the study area,and laboratory experiments were carried out to measure the oil viscosity,gum content,wax content and group components of oil samples at different well locations,and to analyze the plane variation rule and influencing factors of oil viscosity.On this basis,the start-up pressure gradient measurement experiment is carried out,and the variation law of start-up pressure gradient with crude oil viscosity and core permeability is analyzed through the experiment to determine the start-up pressure gradient range,which provides theoretical support for development well pattern design.The geological model of sedimentary units in the study area was established by using Petrel geological modeling software.Based on the dynamic and static data of the study area,the fine geological model of the study area is established;The remaining oil distribution is studied by using the method of combining 3d fine geological modeling and reservoir numerical simulation on the basis of fully studying the geological and sedimentary characteristics of reservoir and the law of oil and water movement;Finally,according to the production speed,well pattern density,water flooding control degree and other factors to complete the optimization of well spacing.make development efficiency and economic index forecast.Research findings include:(1)It can be obtained through object model experiment:The viscosity measurement experiment shows that obvious heavy oil is formed in the expanded area,and the average crude oil viscosity reaches 203.9m Pa·s.According to the distribution of crude oil viscosity on the plane,the change of east-west direction is not obvious,but shows a trend of obvious increase from south to north.This is because the closer to the oil-water boundary,the higher the content of glue and asphaltene,the higher the viscosity;The start-up pressure gradient experiment shows that the start-up pressure in the study area is between 0 and0.07253;The starting pressure gradient decreases with the increase of core permeability and increases with the increase of crude oil viscosity.(2)It can be obtained through numerical simulation:The remaining oil is analyzed and compared through geological modeling,and the reserves of S^?4+5a?S^?S1-S2and S^?1+2Bare relatively high;Combined with the technical and economic limit well spacing,the well spacing range is determined to be132m-175m,the reasonable well spacing is determined as 150m through numerical simulation;From the perspective of water flooding control degree and oil recovery rate,the optimal well pattern transformation form in the study area is obtained,The reverse nine-spot pattern was firstly exploited,and the five-point pattern was converted to when the water cut was 70%,and the final recovery factor is estimated to be 29.8%.