IMPROVING WELL CEMENTING PROCESSES AS A FOUNDATION FOR QUALITY MANAGEMENT IN WELL CONSTRUCTION AT OIL AND GAS ENTERPRISES

Abstract

This article investigates the enhancement of well casing and cementing technologies for low reservoir pressures. The study focuses on the effective removal of clay and sludge deposits from borehole cavities and the optimization of cement slurry compositions (including lightweight systems). These improvements are essential for forming a durable, impermeable cement sheath and enhancing the operational reliability of oil and gas wells.

The research establishes that in intervals with significant cavitation and reduced reservoir pressures, conventional lightweight cement materials result in a weakened, heterogeneous set cement with poor bonding to the casing and formation, failing to provide adequate zonal isolation. The limited efficacy of traditional mechanical wellbore cleaning methods is demonstrated, highlighting the advantages of an interval-specific hydraulic tool designed to intensify the removal of clay and sludge deposits. Laboratory studies of strength development under downhole thermobaric conditions revealed substantially lower and slower-growing compressive strength in lightweight systems compared to conventional-density slurries. This finding underscores the necessity of optimizing their formulations with regard to sedimentation stability and set cement microstructure.

The obtained results enable the improvement of well casing and cementing technologies in cavernous wellbores under low reservoir pressures through the targeted selection of cavity cleaning methods and the optimization of lightweight cement slurry compositions. The proposed approaches can be applied in the design of production well cementing to enhance zonal isolation reliability and mitigate the risk of subsequent remedial cementing operations.