Optimal Waterflood Management Using Rate Control

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractField scale rate optimization problems often involve highly complex reservoir models, production and facilities related constraints and a large number of unknowns. All these make optimal reservoir management via rate and flood front control difficult without efficient optimization tools. Some aspects of the optimization problem have been studied before using mainly optimal control theory. However, the applications todate have been limited to rather small problems because of the computation time and the complexities associated with the formulation and solution of adjoint equations. Field-scale rate optimization for maximizing waterflood sweep efficiency under realistic field conditions has still remained largely unexplored.We propose a practical and efficient approach for computing optimal injection and production rates and thereby manage the waterflood front to maximize sweep efficiency and delay the arrival time to minimize water cycling. Our work relies on equalizing the arrival times of the waterfront at all producers within selected sub-regions of a water flood project. The arrival time optimization has favorable quasilinear properties and the optimization proceeds smoothly even if our initial conditions are far from the solution. Furthermore, the sensitivity of the arrival time with respect to injection and production rates can be calculated analytically using a single flow simulation. This makes our approach computationally efficient and suitable for large-scale field applications. The arrival time optimization ensures appropriate rate allocation and flood front management by delaying the water breakthrough at the producing wells.Multiple examples are presented to support the robustness and efficiency of the proposed optimization scheme. These include several 2D synthetic examples for validation purposes and a 3D field application. In addition, we demonstrate the potential of the approach to optimize the flow profile along injection/production segments of horizontal-smart wells

Zwitterionic Dipicolinic Acid-Based Tracers for Reservoir Surveillance Application

“…Pertaining to oilfield management, interwell tracer tests (IWTTs) serve as a direct method of investigating fluid flow paths between and/or among injector and producer wells to enhance mapping of reservoir heterogeneity . Effective identification of productive wells and fluid cycling, as given by cross-well tracer data, serve to highlight its particularly informative role in waterflood rate management, among other aspects . Further, for mature fields under peripheral water flooding programs that could benefit from infill drilling, implementation of a full-field cross-well tracer program that elucidates the existence of faults and high-permeability zones will greatly reduce uncertainties related to waterflood management and thereby justify implementation of expensive drilling/workover programs .…”

“…Effective identification of productive wells and fluid cycling, as given by cross-well tracer data, serve to highlight its particularly informative role in waterflood rate management, among other aspects . Further, for mature fields under peripheral water flooding programs that could benefit from infill drilling, implementation of a full-field cross-well tracer program that elucidates the existence of faults and high-permeability zones will greatly reduce uncertainties related to waterflood management and thereby justify implementation of expensive drilling/workover programs . In the context of tracer material development, one of the primary concerns is the potential loss of tracer materials to the subsurface due to adsorption and/or destabilization under high-temperature and high-salinity reservoir conditions.…”

A Prediction Method for Flow-Stop Time in Deep-Water Volatile Oilfields: A Case Study of Akpo Oilfield in Niger Delta Basin

“…At present, many researchers have been conducted the water-cut changing law in water-flooding oilfields, which can be roughly divided into two categories as described as theoretical formula methods and empirical formula methods [19][20][21][22]. In terms of theoretical formula methods, it can be traced back to the classical theory Buckley-Leverett equation proposed by Buckley and Leverett [23], which for the first time elaborated the water flood mechanism in detail.…”

Optimasi Laju Injeksi Pada Sumur Kandidat Convert to Injection (CTI) di Area X Lapangan Y

“…Salah satu metode secondary recovery yang paling umum digunakan untuk meningkatkan produksi ialah waterflooding (Alhuthali, Oyerinde, Gupta, 2006). Waterflooding merupakan metode penginjeksian fluida ke dalam reservoir, di mana air sebagai media injeksi akan diinjeksikan ke dalam reservoir sehingga diharapkan air akan mendorong minyak yang ada pada lapisan reservoir untuk sampai ke sumur produksi dan sampai ke permukaan (El-khatib, 2001;Thomas, 2001).…”