Research On Deep Profile Control And Water Shutoff Technology In Huang 3 Chang 8 Block Of Jiyuan Oilfield

The characteristics of low permeable fracture and pore distribution,fracture development imperfect,made the geological complex,serious vertical and plane heterogeneity Huang 3 Chang 8 reservoir of JiYuan oilfield.After water flooding breakthrough in oil well,water cut rising rapidly.Low degree of water flooding,resulted in large amount of oil remaining in cracks and pores.Therefore,a single deep profile control technology was not suitable for low permeability fractured reservoir.In the thesis,complex slug of deep profile control water plugging technology,namely high strength plugging agent to plug big fissure water channel and the water flooding divert agent to improve the swept volume,was researched.The strength of the water flooding divert agent was moderate,rise to "tune" and "drive" the combination of effective displacement of crude oil in porous medium and small cracks.In the experiment,the formula and characters of plugging agent were investigated.The formula for plugging agent comprised of associating polymer(ZND-5),citric acid root/aluminum ion and stabilizer retarder.Optimized associating polymer concentration ranged from 2000 mg/L to 4000 mg/L,the agent citric acid root payable/aluminum ion concentration ranged from 100 mg/L to 200 mg/L,the better dosage of stabilizer was 800 mg/L,and retarder tartaric acid sodium concentration was 160 mg/L.Plugging agent in the Huang 3 Chang 8 formation conditions(total salinity of 67463 mg/L,48.5?)showed excellent salt resistance and shear resistance.3000 mg/L and 4000 mg/L ZND-5 plugging agent plugging rate were as high as 98.71%and 99.64%.The breakthrough pressure gradient in porous media were 6.982 MPa/m and 18.529 MPa/m in the 0.3?m2 porous medium.Profile modified index was up to 85.47%for 3000 mg/L ZND-5 plugging agent.Based on the notion of the near wellbore formation plugging high permeability zone,middle stratum to force water,far well train of thought and action principle of strata displacement,the basic properties of the water flooding divert agent was studied.Under the Huang 3 Chang 8 reservoir,the expansion ratio for divert agent was up to 32 times,and dehydration was not occur during 60 dag of aging.It exhibited heat resistance salt resistance and excellent long-term stability.On the basis of injection timing optimization,complex slug profile control water plugging technology was implemented in the Huang 3 Chang 8 reservoir of JiYuan oilfield.Two rounds of deep profile control water plugging field application was done during the year 2011 to 2013.Circulation channels was effectively blocked,and the subsequent water flooding channels was diverted.Moreover,the decreased water cut,and water injection efficiency was seen.For example,13 saliva flooded Wells reproduced oil,and the amount of oil for single oil well was 1.2 t.After rounds of the profile control water plugging,the total amount of 41 water wells were treated,corresponding to amount of 67 oil well,and 5517.8 t of oil was significantly enhanced.The research achievements of this paper to protect the oilfield Huang 3 long 8 low permeable fracture field application provides strong technical support.Field measures shows that the synchronization of deep profile control and water plugging technology can effectively inhibit water channeling advantage channel,start the low permeability reservoir,the technology in the tableland oilfield has great potential of promotion.