Qualification and Deployment of a Nanocomposite Wellbore Sealant Water-Based Mud for Drilling a High Temperature Well

Abstract

Abstract This paper describes the validation testing and field application of a nanocomposite wellbore sealant (NCWS) in a high temperature well. The inclusion of the NCWS in the high temperature water-based mud (HTWBM) exhibited tight and stable filtration characteristics, measured by high pressure high temperature (HPHT) and permeability plugging tests (PPT), as well as a notable reduction in drilling fluid viscosity. The improvement in rheological profile reduced equivalent circulation density (ECD) and standpipe pressure (SPP). A NCWS was identified during the well planning phase as the ideal technology for addressing the filtration and rheology. A comprehensive suite of laboratory tests was performed to qualify the HTWBM formulation inclusive of NCWS performance, which included PPT and HPHT testing at 150°C. Rheology measurements were performed on a six-speed rheometer at 50°C. The utilization of nanocomposite-treated water-based mud (NCWBM) resulted in notable enhancements in fluid performance as evidenced by the test results and when compared to offset salt polymer fluid formulations. Hydraulic modeling showed reduction in ECD and SPP values using the NCWBM rheology results. The NCWS was used in two wells, and fluid properties achieved exceeded expectations. The improved rheological profile was observed, which reduced the ECD and SPP values while drilling both wells. The stability of the fluid proved consistent and easy to maintain over extended periods ranging from 22 drilling days on the first well to 39 days on the second well. Wireline logging operations have been performed successfully, eliminating issues experienced on offset wells. Tight hole conditions while carrying out logging operations had increased the time required to successfully complete the data acquisition scope. The inclusion of the NCWS in the HTWBM formulation resulted in some simplification of the fluid whereby two polymeric fluid loss additives were removed and the concentration of two additives was reduced by 50% and 75% respectively. The simplification of the fluid formulation resulted in more efficient logistics and lower inventory holding at the rig site, as well as a reduction in the lifting operations, and reduced manual labor required for mixing of the additives. The NCWS was the key technology that developed the unique properties for the WBM. The NCWS is a proprietary nanocomposite suspension that provides enhanced sealing capacity to water-based drilling fluids. The additive is produced and applied as an emulsion and thus avoids the inhalation hazards associated with handling of dry nanomaterials (Jay P. Deville, Preston A. May, and J. J. Miller 2022; Fröhlich and Salar - Behzadi 2014).