Study On Chemical Viscosity Reduction And Drag Reduction Technology For Tahe Heavy Oil Formation

This article focuses on the characteristics of high viscosity and poor fluidity of Tahe heavy oil.By studying the main factors affecting the viscosity of crude oil,a SDR-2 viscosity reducer with good applicability to Tahe heavy oil was developed,and the temperature-resistance,salt-resistance,and applicability of the viscosity reducer were also studied.The viscosity reduction mechanism of viscosity reducer was analyzed by studying the emulsifying state,interfacial tension and interfacial shear viscosity when the viscosity reducer and crude oil acted.The results show that Tahe crude oil has a high degree of condensation,H/C atomic ratio between 1.36-1.53,and high asphaltene content is a key factor in the viscosity of crude oil.The four components of crude oil have different effects on the viscosity of crude oil.The order from small to large is:saturated<aromatic<colloid<asphaltene.By comparing the SDR series viscosity reducer,the SDR-2 viscosity reducer with better viscosity reduction effect is selected.SDR-2 viscosity reducer has good applicability to heavy oils with viscosity of 2.0×10~5 mPa·s,8.0×10~5 mPa·s,and greater than 1.0×10~6mPa·s,and has high temperature of 140°C and high salinity of 2.4×10~5 mg/L,the viscosity-reducing effect can still be maintained at more than 99%.At the same time,SDR-2 viscosity-reducing agent has good compatibility with on-site demulsifiers.Using a strata simulation device to simulate the viscosity reducing effect of the viscosity reducing agent under the formation conditions,the viscosity reduction rate can reach94%-96%.SDR-2 viscosity reducer can effectively reduce the interfacial tension between heavy oil and water,make oil form an oil-in-water emulsion,greatly reduce the flow resistance,has a good effect of reducing viscosity and drag.