Reservoir to Tank: Fit for Purpose Integrated Workflows for Waterflood Management and Production Enhancement

Abstract

Integrated solutions are important to formulate plans for mature reservoirs under waterflooding due to related dynamic changes and uncertainties. The reservoir and field management need to be handled as an integrated system, and therefore needing a multidisciplinary approach. This paper demonstrates how the integrated multidisciplinary team has developed several workflows covering water-flooding management, production enhancement and maximizing the economic recovery of reservoirs in the North Kuwait asset. Many integrated workflows were developed for water flooding and production optimization. The main integrated workflows that were implemented are as follows: PVT Properties Tool: is designed to estimate the fluid properties throughout the reservoir taking into consideration areal and vertical variations based on trends, and existing data coverage. Opportunity Maps: is a combination of updated reservoir pressure and fluids properties to provide a fast way to identify areas of opportunity to increase/decrease injection or production based on the development strategy. Waterflooding Patterns/segments Review Workflow and Allowable Tool: This integrated analytical workflow applied on predefined reservoir patterns or segments based on geological distribution and/or hydraulic communication, includes several tools like the analysis of production and injection trends, diagnostic plots to assess good vs bad water, Hall plots, Reservoir Pressure data, tracer data, salinity changes and pump intake pressure trends. Geological analysis (cross-sections, well correlations, sand thickness maps) for each layer are integrated in each pattern/segment review to support reservoir connectivity (or the lack thereof). Instantaneous and cumulative VRR are calculated and compared with the overall exploitation strategy and water injection efficiency. Other sub-workflows were developed to improve and manage waterflooding performance such as water recirculation tool and streamline sector modeling simulation. Structured integrated proactive production and ESP optimization workflows: Production optimization is a continuous iterative process (cycles) to improve production, especially in mature fields. This workflow facilitates the identification of opportunities for production optimization with a pro-active approach focusing on flowing wells and rig-less interventions to tackle production challenges and achieve production targets. The Heterogeneity Index (HI) process is utilized to rapidly demonstrate production gain opportunities. This provides family-type problems that are then represented by type-wells for detailed diagnostics. Continuous application and embedding of such structured integrated workflows as standard best practices, deliver significant value in terms of improving the understanding of reservoir performance in order to inject smart (where and when required) and produce smart (sweet healthy spots). This is done on reservoir, segment, pattern and individual well levels in multidisciplinary team domains. The ultimate results reflected in continuous improvement in waterflooding management (injection efficiency, vertical and areal sweep efficiency, sweep new oil via changing streamlines). This in turn contributes to significant added oil gain and recoverable reserves with best practices reservoir management. These integrated workflows are user friendly and can be applied across different reservoirs and fields. The application of such workflows in a structured, consistent and proactive approach improves the overall asset management in terms of maximizing production and recoverable reserves.