Studies On Water Shutoff Without Pulling String In The Chengdao Oil Field

As for Chengdao Oilfield belong to offshore oil field, so exist limitations of water shutoff .When oil well Water Shutoff ,it ask for without Pulling String ,and water shutoff agent ask for make up with sea water , environmentally and resistant to shear . The key aspects about water shutoff without Pulling String in the Chengdao Oil Field were studied in this paper, including water shutoff agent, matching treatment fluid and water shutoff technology etc. Gel-type and frothy gel type water shutoff agents were chosen for further study according to the formation conditions of the Chendao oil field. oxido reduction chromium gel, organic chromium gel and phenolic resin gel were studied for Gel-typ, which is about gel application properties including gelation time, gel strength, resistance to shearing, shut off capacity and resistance to erosion etc. This research gains a serial of gel formulation with adjustable gelation time, strength and satisfactory stability. Optimise gas, optimise foaming agent, optimise stabilite agent and optimise Gel formula were chosen for frothy gel type water shutoff agents further study. Preflush,afterflush and gel breaker agents were studied at the Chengdao condition, obtaining preflush formulations fit forChengdao oil sample and gel breaker agents formulations. Studied the water shutoff method ,witch pre-treatment formation with high concentration of polymer, optimize water shutoff parameters by means of perpendicularity test, including mass fraction of polymer, intake volume of polymer, injection rate of polymer and permeability. Experiments show that the means of water shutoff without Pulling String can blank off water yield formation and safeguard oil layer, enhanced oil recovery apparently. According to the laboratory testing, water shutoff implement forCB11A-1,and attaind preferable water shutoff effectiveness.