| The deep heavy oil reservoir in Lukeqin area average permeability of 230×10-3 m2,the coefficient of variation was 0.94,the viscosity of the crude oil of 286-586mPa·s 100252-174925mg/L,the salinity of formation water,formation temperature of 78 DEG C,using conventional water flooding,calibration recovery is only 13.5~15.8%.Due to the adverse mobility ratio and the development of 8 years,the water cut is 71% water.Flooding degree of 6.2%,has entered the stage of high water development,water flooding is becoming increasingly prominent,the urgent need to explore a substantial increase in Lukeqin heavy oil recovery technology.Aiming to the main problems in Lukeqin heavy oil reservoir characteristics and water flooding development,combining the advantages of foam flooding,studies show that the apparent viscosity of foam is higher,can effectively reduce the mobility ratio,which enlarge the swept volume effect,eventually reaching the EOR project,is better than that of pure nitrogen flooding and foam flooding.Based on the laboratory tests were screened for XHY-4 type Lukeqin heavy oil reservoir of the foaming agent,the foaming agent in high temperature and high salinity(80 C,160000mg/L)under the condition of the foaming rate is greater than 600%,the half-life of more than 600 s,with excellent foaming properties and foam stability performance.Combined with the physical model and mathematical model of optimization design of injection parameters the total slug is 0.45 PV,the alternating injection of gas and liquid foam formation method,gas-liquid ratio 1:1,alternating cycle 15 days,can be predicted in the water flooding to enhance the recovery rate of 6.8%.and then start the pilot test area of gas injection,a total of 14 rounds of alternating injection,19 wells test area a total of 14 wells were effective,total number of wells 73%,water content decreased by 52.4%,the cumulative increase of oil 17627 t,the natural decline rate and water rate declined sharply,fully proved that foam flooding is an effective way to improve the Lukeqin deep heavy oil recovery.In order to further verify the test results,test drive and nitrogen nitrogen respectively.Two kinds of foam flooding displacement method,the EOR effect is more obvious.The research results of Lukeqin deep heavy oil oilfield EOR,which has important guiding significance to realize the sustainable development of oil field. |
