The Study Of Sensitivity Evaluation And Reservoir Protection Technology Of Jin621Block

Reservoir protection technologies is very important in enhancing the success rate ofprospecting well, discovering and promoting the accurate evaluation of oil and gas layer,improving the success rate of well stimulation, enhancing reservoir recovery and efficienteconomic development. Since1990s, shielding temporary plugging technology has beenwidely applied in the domestic major oil fields. Especially in the low permeability andfractured reservoirs, the application effect is good. Shielding temporary plugging technologycan translate the negative factors into favorable factors for protecting the reservoirs in theprocess of drilling oil and gas layer, and a protection zone near well bore can be formed inshort time of reservoir drilling which the permeability is zero or approach zero, then thedamage of oil and gas layer by the drilling fluid and cement slurry can be reduced and thereservoir is protected.According to Jin612block of Liaohe Oilfield, this paper through the analysis ofgeological characteristics, sensitivity evaluation and experimental research, we have acomprehensive understanding to target oil layer in Jin612block in the geologicalcharacteristics, physical property of rocks; a comprehensive understanding to determine thetype, content and distribution characteristics of sensitive minerals in rocks. Using fractaltheory to the optimization of shielding temporary plugging agent, and is verified byexperimental study that the optimized agent can quickly and efficiently form shieldingtemporary plugging ring of shallow depth and high strength, with better protection effect ofoil and gas layer than traditional methods. From the perspective of economic andenvironmental protection meanwhile, recommend a set of aqueous film forming drilling fluidsystem suitable for liaohe oilfield jin612block, which has good reservoir protection effect,and permeability recovery value can be up to90%on average. The results of the studyprovided a reliable basis and suggestions for making plan of oil and gas protection and theconfirmation of the drilling fluid system in drilling process of jin612block in liaohe oilfield,to achieve the purpose of protecting layer and preventing oil and gas reservoir damage.