Study On Gas Injection Improvement And Development Effect Of Fault Block 44 In Liuxi Oilfield

Located in Xianxian County,Heibei province,the Fault-Block 44 of Liuxi Oilfield Road is affiliated to PetroChina Huabei Oilfield Company.It is characterized by low-porosity and low-permeability and it's reported as abundant oil-bearing reserves,in particular the crude oil.Due to a lack of formation energy,supplementary energy for formation is needed.As it was developed in 2005,its initial production was considerable but it was soon followed by a sharp decline in production.It has also been challenged by high injecting pressure and poor efficiency.And there has been a dilemma of "hard to inject or hard to extract".In view of this,gas injection and flooding is an important method to increase crude oil recovery efficiency and development efficiency at Fault-Block 44.This paper aims at gas injection and flooding of the fault block 44 of Liuxi Oilfield.First of all,the geology and reservoir characteristics of this block are studied.It is found that the permeability of the block is low,and the rock properties of the reservoir are relatively low.Poor,crude oil is difficult to flow in the strata,and water injection is difficult.The analysis of reservoirs undergoes reservoir transformation,current production and development status,and reasons for water injection difficulties;Then,the theoretical analysis of gas injection feasibility was carried out to study the mechanism of gas injection and flooding and the phase change of the system during gas injectioa According to the actual conditions of the block,the gas medium such as CO2 was determined and the CO2 was analyzed.After the oil displacement mechanism,an indoor test program was developed.The gas injection expansion experiment to study the effect of CO2 injection on the physical properties of crude oil,the fine tube experiment to study the minimum miscibility pressure,and the long core experiment to determine the injection parameters were carried out.The results show that the crude oil of Road No.44 block has good solubility to CO2 and can improve its physical properties after injection.The starting pressure is not high.Within the maximum pressure range,it is suitable for gas injection and flooding to improve the development effect.Finally,combined with the results of the indoor test,the gas injection improvement and development effect plan for the block No.44 of Liuxi Oilfield Road was formulated and the implementation requirements of the plan were...