Study Of Sweep Efficiency Of Water Injection Under Fracturinq-conditions Process

Water injection performance depends on the petrophysical reservoir properties and fluid-flow characteristics. Reservoir simulation models should include rock properties variation and rock-fluid interactions and, when it is necessary, geomechanical phenomena. When water Injection above Fracture Propagation Pressure (IFPP) is used, its effects over the reservoir model performance, and specially, on waterflooding sweep efficiency, become a critical point to be assessed. Quantification of these effects using parameters such as the Recovery Factor (FR) and Net Present Value (NPV) is important for the water injection project dimensioning and to determine the feasibility and usefulness of the injection process to be implemented. Water injection under fracturing conditions is an important method to overcome the production decline caused by the injectivity loss in reservoirs with water injection. Also, the modeling of injectivity loss and fracturing processes are subject of several studies, which aim to understand these processes in order to enhance the results to be used for the reservoir development strategy proposal. The objective of this work is to quantify, using Sweep Efficiency and NPV as study parameters, the effects of anisotropics on the production performance during a waterflooding under fracturing conditions. The methodology proposed considers the simulation of scenarios in which the injectivity loss is represented by an analytical decline model, and the fracture is represented using a virtual horizontal well. This proposal is implemented in order to show the effect of the water injection - injectivity loss - fracturing process on the reservoir behavior. Three different fluid models were used to illustrate their effect in some production parameters and usefulness of fracturing process in several scenarios. The results show the applicability of water injection under fracturing conditions in different scenarios. In addition, this work shows the importance of the reservoir parameters into the injectivity loss and fracture propagation models, the significance of the FR and NPV in the quantification of these effects. Finally, the relation between the heterogeneity degree and production parameters is presented. Copyright 2007, Society of Petroleum Engineers.311671175Altoé, J.E., Effects of Oil-Water Mobility on Injectivity Impairment due to Suspended Particles 2004 SPE Asia Pacific Oil and Gas Conference, , paper SPE 88501 presented at the, Perth, October 18-20Palsson, B. et al.: A Holistic Review of the Water Injection Process, paper SPE 82224 presented at the 2003 SPE European Formation Damage Conference, The Hague, May 13-14Souza, A.L.S., Water Management in Petrobras: Developments and Challenges 2005 Offshore Technology Conference, , paper OTC 17258 presented at the, Houston, May 2-5Ovens, J.E.V., Making Sense of Water Injection Fractures in the Dan Field (1998) SPERE, 1, p. 556. , DecemberAli, N., Injection Above Parting Pressure Waterflood Pilot, Valhall Field, Norway (1994) SPERE, 9, p. 22. , FebruaryVan den Hoek, P.J., Impact of Induced Fractures on Sweep and Reservoir Management in Pattern Floods (2004) 2004 SPE Annual Technical Conference and Exhibition, , paper SPE 90968 presented at the, Houston, Sept. 26-29Gadde, P.B., Growing Injection Well Fractures and Their Impact on Waterflood Performance 2001 SPE Annual Technical Conference and Exhibition, , paper SPE 71614 presented at the, New Orleans, Sept. 30, Oct. 3Montoya Moreno, J.M., Well Impairment Upscaling Applied to Water Injection Above Fracture Pressure Simulation 2006 XXVII CILAMCE - Iberian Latin American Congress on Computational Methods in Engineering, , paper CIL28-502 presented at the, Belém, Sept. 3-6Souza, A.L.S., The Impact of Injection with Fracture Propagation During Waterflooding Process 2005 SPE Latin American and Caribbean Petroleum Engineering Conference, , paper 94704 presented at the, Rio de Janeiro, Jun. 20-23Devloo, P.R.B., Modelagem Numérica de Fraturamento Hidráulico 2001 XXII CILAMCE - Iberian Latim Americain Congress on Computational Methods in Engineering, , paper presented at the, Campinas, Nov. 7-9Ji, L., Methods for Modeling Dynamic Fractures in Coupled and Geomechanis Simulation 2004 SPE Annual Technical Conference and Exhibition, , paper 90874 presented at the, Houston, Sept. 26, 29Maschio, C., A New Upscaling Technique Based on Dykstra-Parsons Coefficient: Evaluation with Streamline Reservoir Simulation (2003) JPSE, 40, p. 27. , OctoberMuñoz Mazo, E.O., Efeito do Acoplamento da Geomecânica à Simulação Numérica de Reservatórios com Injeção de Água a Pressão Acima da Pressão de Fratura (2006) 2006 Rio Oil & Gas Exposition and Conference, , paper IBP1581-06 presented at the, Rio de Janeiro, Sept. 11, 1