Flood Management with floodOPT

For mature fields, significant optimization potential exists simply by updating well rates that promote sweep vs. fluid cycling to realign patterns.  Unfortunately, engineers typically only know which producers are high watercut or high water rate wells, but not which injectors are responsible for these effects making realignment difficult.  Using Streamsim's streamline-based analysis, injector-producer pairs are easily computed to quantify all well-pair connections at any given time.  Next, floodOPT takes this well-pair information, along with current watercuts to identify fluid cycling vs efficient sweep.  The goal of floodOPT is to provide new well rate targets for both injectors and producers that prompt the effcient connections and demote the inefficient connections. In this manner, floodOPT provides a systematic reservoir engineering approach, based on historical injection/production data, dynamic patterns and allocation factors, to give next month's well rate targets. 

 

More Info: PricingSPE Paper, SPE Paper Presentation

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The floodOPT Workflow

One powerful aspect of streamline simulation is the ability to create a snapshot of which injectors support which producers, and how much fluid is allocated between injector/producer pairs. Thus it is possible to related injected water volumes to off-set oil production down to a well-pair level and be displayed using Streamsim's patented Flux Pattern map (FPmap). 

Since offset oil production is related to water injection this information can also be displayed in a cross-plot for every injector in the field at any given point in time.  This novel information leads to the idea of injection efficiencies--a ratio of off-set oil production to water injected--which in turn can be used to manage the flood. The injection efficiency is defined as the ratio of off-set oil production to water injected. Note the following about the injection efficiency:

 

  • There is an injection efficiency for each well pair (connection) as well as for each active injector in the field. The offset oil production (numerator) must be calculated using the information from the well allocation data supplied by the streamlines. On a per-injector basis this is the IEplot within studioSL.
  • The injection efficiency is a ratio of rates and therefore represent an instantaneous metric. However, the equation applies just as well to cumulative volumes (conformance plot).
  • The definition of an efficiency can be extended to any type of injected and produced volumes and therefore can be used for gas injection as well as WAG injection or polymer injection, for example.

 

 

Once the injection efficiency is known for each well-pair, efficient producers and efficient injectors are known, as well as inefficient producers and inefficient injectors.  Next, new rates which promote good connections vs. poor connections can be computed, and a plot or listing of suggested well rate changes is given (as in the figure at right). Because the definition of good vs. poor is arbitray, the user can set this based on economic watercut, field water cut, or a specific value. This definiton, along with min and max allowable rate changes, defined a weighting function that gives the updated well rates for each defintion scenaro.

For details see on floodOPT, the weight funciton, and workflow see Thiele, M.R. and Batycky, R.P.; "Using Streamline-Derived Injection Efficiencies for Improved Waterflood Management," SPEREE April 2006, Vol 9, No 2, pp187-196.

Features

floodOPT is based on either a surveillance or simulation model and allows to:

  • Generate rate targets for any number of injectors and producers
  • Apply field injection rate constraints as well rate constraints to the final target rates.
  • Define what a good vs. poor connection is based on field average water cut, group water cut, or economic limit water cut. 
  • Automatically pass rate targets back to 3DSL (or Eclipse) for forecasting in a simulation model.
  • Export rate targets to Excel.
  • When using multiple geological models (see Uncertainty Quantification) display the range in well target rates across all models.
floodOPT Example Workflow within studioSL

studioSL offers a convenient way to apply floodOPT to a 3DSL run for flood management purposes and forecasting. The starting point is a 3DSL simulation with an acceptable well-level history match (see more about history matching here). The well-level history match is an important component of any reliable forecast. Since floodOPT uses well-pair injection/production information, an acceptable well-level history matching is an important pre-requisite for applying the workflow. The basic steps in a floodOPT workflow are:

  1. Select a 3DSL base run (history matched) from which to start the floodOPT workflow.
  2. Select wells for which rate changes are desired. Set constraints as necessary (min/max injection/production targets). Set parameters for the weighing used in translating well-pair efficiencies into rate increases/decreases.
  3. Calculate new rates to use for forecast run.
  4. Decide on time step to take before updating target rates again. Return to 2.

Download our surveillance dataset here.

Follow our surveillance tutorial here, to create the FPmap from the production data.

Follow our floodopt tutorial here, to create a floodOPT project.

Contact in USA

Corporate Headquarters 
StreamSim Technologies, Inc.
865 25th Avenue
San Francisco, CA 94121
U.S.A.

Tel: (415) 386-0165

Contact in Canada

Canada Office 
StreamSim Technologies, Inc.
Suite 102A - 625 14th Street N.W.
Calgary, Alberta T2N 2A1
Canada

Tel: (403) 270-3945

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