Optimal Well Placement in Heterogeneous Reservoirs Via Semi-Analytic Modeling

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe need for accurate well productivity models with arbitrary well trajectories spurred a revival in analytic solution methodology for fluid transport problems.Analytic formulations often depict single phase flow throughout the reservoir. The Babu-Odeh horizontal well solution for a boxshaped reservoir with spatially invariant properties is generalized here to allow closed-form solutions for heterogeneous media. A reservoir is decomposed into interacting regions, each with its own reservoir properties and associated analytic potential flow solution. Using wellestablished boundary element techniques, pressure and flux continuity are imposed at selected interface points to solve for the steady material exchange between regions. Constant pressure and zero flux features (fractures and barriers) are easily entertained at region boundaries. The 2-D, pseudosteady state solution for heterogeneous media is embedded within a reservoir performance feedback loop of a powerful gradient search method to produce a robust optimal in-fill well placement algorithm. Utilizing this approach, new criteria are developed concerning optimal placement of vertical wells for primary production with respect to heterogeneity, asymmetry, and anisotropy. The semi-analytic method has been extended to 3-dimensional flows to serve as a compute engine for a new generation of reservoir management and optimization tools.

Well placement optimization: A survey with special focus on application for gas/gas-condensate reservoirs

“…Their method is based on geometrical and fluid mechanics approximation steps. Hazlett and Babu (2005) presented a well placement method where they used a semianalytical reservoir simulation model to calculate the reservoir feedback. Their simulator was based on the boundary element method (BEM).…”

A practical approach for optimization of infill well placement in tight gas reservoirs

“…In many cases, wells are planned to maximize well cumulative production or net present value (NPV). Sometimes, optimization of infill well productivity index is the main concern (Hazlett and Babu, 1989). In this study, we use net increase in field cumulative production due to addition of an infill well to select and rank infill well candidates.…”

“…It should be also noted that optimal infill well placement may have different meanings under different design considerations (Hazlett and Babu, 1989). In many cases, wells are planned to maximize well cumulative production or net present value (NPV).…”

Optimal Infill Drilling Design for Marginal Gas Reservoirs Using a Simulation-Based Inversion Approach

“…12 In many cases, wells are planned to maximize well cumulative production or net present value (NPV). Sometimes, optimization of infill well productivity index is the main concern.…”