Research and Application of Integrated Viscosity Reduction, Fracturing, and Sand Control Technology for Productivity Enhancement in Heavy Oil Sand-Producing Reservoirs of W Oilfield

To address development challenges in W Oilfield's heavy oil sand-producing reservoirs - including high crude oil viscosity (surface degassed oil viscosity 4520–7880 mPa·s), poor fluidity, and productivity inhibition caused by strong sand-carrying capacity - this study proposes an integrated technology combining viscosity reduction, fracturing, and sand control. Focusing on reservoir geological characterization, technical system development, and field application evaluation, the research optimized key parameters through laboratory experiments. Based on analysis of rock mechanical properties, fluid characteristics, and sand production patterns in target blocks, the JN-01 viscosity reducer (with viscosity reduction rate exceeding 90%) was selected along with compatible fracturing fluids and sand control materials. Differentiated sand control process sequences were designed according to well section length, featuring collaborative implementation of “fracture creation & viscosity reduction + coated sand artificial barrier” and “fracture creation & viscosity reduction + mechanical wellbore sand control”. Field tests on 8 wells demonstrated increased daily production per well from 3 tons to 5.2 tons, reduced sand content from 1.3% to below 0.05%, and stable production exceeding 13 months. This achievement provides a novel technical approach for efficient development of similar heavy oil reservoirs while advancing China's autonomous innovation in complex reservoir exploitation. Post-application projections indicate a 5.8-percentage-point increase in block recovery factor, effectively supporting oilfield production stabilization and efficiency improvement goals.