Investigation of a Solid Particle Deposition Velocity in Drag Reducing Fluids with Salinity

In an extended-reach horizontal well, the efficient removal of solid cuttings during drilling operations is important for smooth and low-cost drilling operations. The efficient removal of suspended solids during the transportation of crude petroleum is also essential for ensuring the effective extraction, separation, and processing of oil and gas streams. One of the key factors that play an important role in the removal of solids during drilling is the terminal settling or depositional velocity (V_s) of the solid cuttings. Quantifying Vs through experiments helps us to calculate the time required to settle a solid particle during the connection time when the fluid circulation velocity is stopped. At this stage, when fluid circulation is halted, it is essential to know the critical settling velocity of the cuttings. The knowledge of settling velocity or depositional velocity of the cuttings allows evaluating the accurate timings for pipe connection and also helps in the prevention of solid deposition in the extended reach horizontal well. In this study, Partially-hydrolyzed polyacrylamide (PHPA) is used as an additive in water-based drilling mud as a drag-reducing fluid. We have investigated the effects of salinity on solid particle settling velocity (Vs) in drag-reducing fluids. We prepared the drag-reducing fluid using PHPA, a partially-hydrolyzed polyacrylamide chemical. PHPA (drag-reducing fluid) acts as a turbulence inhibitor. PHPA acts as a drag-reducing fluid (less pressure loss) for drilling since the polymer chain suppresses any turbulence in the flow, reducing the turbulent eddy viscosity. PHPA also helps to seal the fracture in the formation during drilling. We have investigated the drag-reducing effect on the settling velocity of solid particles (drill cuttings) with and without the presence of salt in the fluid. The knowledge from the study on settling velocity will also help us to advance the settling velocity experiments in drag-reducing PHPA solutions.