Evaluations to Mitigate Water Coning and Sand Production by Integrating LWD Technology with Completion Designs

Abstract

AbstractHorizontal and multilateral completions have become increasingly popular as operating companies strive to maximize oil production and minimize the number of wells in Gulf of Mexico (GOM) Shelf. Horizontal oil producers are challenged by gas or water coning that can shorten the well life due to variation in wellbore pressure and reservoir properties from toe to heel. Differences in permeability and/or water saturation, undulations in the wellbore and toe to heel frictional pressure drop can all contribute to early gas or water coning. GOM Shelf sands are predominantly un-consolidated and therefore require appropriate drilling BHAs with placement strategies along with suitable sand control to prevent accumulation in the wellbore and/or erosion of down hole completion components and surface facilities. GOM Shelf sands can contain abundant fines and are non-uniform. The particle size distribution often varies with depth and along the wellbore, thereby making sand control a major challenge.This study descends on an existing GOM Shelf horizontal well that was completed with prepacked screens that sanded in and plugged the well after five years of high water production. A recent reservoir saturation logging run across the reservoir near the toe-end of the lateral granted the viability to revisit this reservoir. Consequently, a new offset horizontal was proposed next to the existing one to sweep out the remaining recoverable reserves. Studies based on existing field data and history match were used to evaluate drilling, well placement, and completion design. Simulations were performed to evaluate attic placement methodology and the inclusion of Inflow Control Devices (ICDs) into the sand control completion and to optimize the integrated design. The results illustrates that attic placement is feasible using azimuthal resistivity measurement with the integration of ICDs to not only delay water coning but also choke back any water that might eventually migrate into the wellbore. Finally, the ICD modeling demonstrates improved sweep efficiency from toe to heel. Both water/gas coning and sand production impose significant risks for lateral well placement and completion design in GOM Shelf especially in horizontal and multilaterals wells. This paper addresses these risks and proposes optimum well placement drilling strategies and completion design to mitigate them.