Water Injection Optimization Using a Streamline-Based Workflow

Abstract

Water Injection Optimization Using a Streamline-Based Workflow Marco R. Thiele; Marco R. Thiele Streamsim Technologies Search for other works by this author on: This Site Google Scholar Rod. P. Batycky Rod. P. Batycky Streamsim Technologies Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, October 2003. Paper Number: SPE-84080-MS https://doi.org/10.2118/84080-MS Published: October 05 2003 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Thiele, Marco R., and Rod. P. Batycky. "Water Injection Optimization Using a Streamline-Based Workflow." Paper presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, October 2003. doi: https://doi.org/10.2118/84080-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractThis paper describes a novel approach to optimize injection and production well rates in a waterflood using streamline-based (SL) flow simulation. The method provides engineers with an approach that is well beyond the traditional field management workflows offered by standard surveillance and finite difference (FD) simulation. The method is automated and therefore applicable to very large fields with many wells.Streamline based flow simulation is unique in that it allows to quantify the amount of injected and produced fluids between well pairs via well allocation factors (WAF's). WAF's allows calculating the efficiency of injection wells as the ratio of injected water to the oil produced at offset wells. With injection efficiencies known across the field for each injector, water can be reallocated from low-efficiency to high efficiency wells, thereby optimizing production for each barrel of water injected.IntroductionFor all but the simplest and smallest floods, areas of water cycling and poor sweep exist as a flood matures. Current flood management is restricted to standard surveillance methods or workflows centered on FD simulation, where areas of by-passed oil are identified and then rate changes, producer/injector conversions, or infill drilling scenarios tested. Identifying and testing improved management scenarios is laborious for large waterfloods - yet it is precisely in these fields where flood management is needed most. For large fields, significant optimization potential exist even without introducing new wells. The goal is simply to achieve more balanced patterns or less injection/production to watered out patterns. However, until now there has been no automated way to identify injection patterns, areas of inefficiency beyond standard surveillance, target well rates, or tie back to reservoir simulation. As we will show, streamline simulation is an ideal tool to help optimize large waterfloods.Streamline-based flow simulation has emerged as a powerful, complimentary tool to more traditional finite difference simulation in the past 10 years. Details on streamline simulation can be found in numerous references and the interested reader is referred to the literature for an extensive discussion on the methodology[1–8].One powerful aspect of streamline simulation is the ability to visualize reservoir flow that results because of well positions, well rates, geological description, and reservoir continuity. At any instant in time, streamlines offer a snapshot of how the reservoir is connected, and how much fluid is allocated between injector/producer pairs. Because streamlines are based on a numerical simulation approach, a streamline model can be calibrated to historical data, account for nonuniform fluid distributions, and multiphase flow effects. Thus, total flow rates as well as phase rates between well pairs can be calculated. This novel information leads to the idea of injection efficiencies, which can automatically identify problem injectors/offset producers to which an optimization method can be applied[10,11]. Because of the automation, the workflow is easily applied to large fields with many wells.Injection EfficiencyThe key concept we use throughout our optimization approach is that of an injection efficiency, which we define as follows:Equation 1Note the following about Eq.:There is an injection efficiency for each active injector in the field. The water injection rate is known (denominator), but the offset oil production (numerator) must be calculated using the information from the WAF's, which in turn are calculated from the streamlines.It is possible to define injection efficiency on an individual producer/injector pair. Then both water injection and offset oil production are computed from the streamlines.The injection efficiency defined as a ratio of rates is an instantaneous one. However, the equation also applies to cumulative volumes, in which case the result would be an average efficiency.Although in this paper we focus exclusively on water injection and oil production, the definition of an efficiency can be extended to any type of injected and produced volumes. Keywords: water injection optimization, injection optimization, aquifer, oil production, streamline, upstream oil & gas, producer, injector, workflow, water management Subjects: Improved and Enhanced Recovery, Reservoir Simulation, Waterflooding This content is only available via PDF. 2003. Society of Petroleum Engineers You can access this article if you purchase or spend a download.