Strategies for Improving Sweep Efficiency and Waterflood Recovery in a Complex Reservoir in the Greater Burgan Field; Learning from a Pilot Water Injection Project and Evaluation Using Sector Model Simulation

Rajan, S.; Al-Naqi, Megdad; Ameen, Alaa Ali; Al-Hashash, Haya Hussain; Madhavan, Sethu; Al-Qattan, Abrar; Al-Enizi, Nawaf Khalaf; Al-Qattan, Mishari Najem; Brooks, Anthony David; Beer, Julian

doi:10.2118/167274-ms

Cited by 2 publications

(1 citation statement)

References 4 publications

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“…Several techniques are used to create a proper approximation of the shared boundary conditions. A widespread procedure is to select the sectors with an irrelevant or even no flux contour and implement a Dirichlet Boundary condition with fixed flux equal to 0 or another constant [1,5,14,16,20,23]. This type of solution is applied to reservoirs with low interaction among wells, when operational changes do not significantly impact the track of streamlines or when the objective is only to simulate a short period of time [2,15].…”

Section: Introductionmentioning

confidence: 99%

Sector modeling using iterative boundary pressure estimation

Barreto

Avansi

Schiozer

2021

J Braz. Soc. Mech. Sci. Eng.

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Simulation of large-scale fields with high-level of heterogeneity are commonly modeled using high-resolution grid cell, which can be time-consuming to run the entire reservoir numerical model. One way to deal with these cases is to split the model into sectors and individually simulate them using artificial boundary conditions to represent the fluid flow among the sectors. However, the representation of the boundary condition can be affected by operational or strategic changes, leading to poor-quality forecasts. This work aims to present a methodology to update the pressure in the boundary of sector models using virtual wells. The methodology consists of balancing the pressure of adjacent sector models over the simulation run. The update procedure is carried out observing boundary block pressure and applying an estimation of the flow rate between sectors and using a pair of virtual wells (producer/injector) to perform it. The methodology was tested in the Brugge Field Benchmark Case, which is a complex case that presents high-interaction activity among the wells. A tree of tests was created to study the parameters of the method, as a different number of times to update the boundary pressure and a different number of pairs of virtual wells. Furthermore, two different ways to split up the reservoir model were also tested: using streamlines and not considering any dynamic flow information, to evaluate the importance of using a technique to select the sectors. The quality of the results was quantified using the indicator called normalized quadratic deviation with sign, comparing the sector simulation and the entire reservoir model simulation. The results show that the methodology was able to improve the quality of the response to all cases. The case splitting the reservoir using streamlines achieved better results, although the improvement of the response was lower than found for the random split. The number of times to update the model was the parameter with a more significant impact on the quality of the results. A higher number of update times tended to achieve better outcomes. The number of virtual wells was the parameter that caused a lower impact on the results, and significant gains in increasing the number of virtual wells were not observed. Therefore, just a few numbers of virtual wells can balance the boundary pressure. To conclude, the proposed methodology can improve the quality of the results for a sector simulation model. The results also show an improvement when the methodology is combined with a splitting procedure of the reservoir using streamlines. The number of times to update the model can significantly affect the results, but the number of virtual wells had a lower impact.

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Section: Introductionmentioning

confidence: 99%

Sector modeling using iterative boundary pressure estimation

Barreto

Avansi

Schiozer

2021

J Braz. Soc. Mech. Sci. Eng.

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A Novel Approach to Developing and Conditioning Part Field Models for a Complex Fluvio-Deltaic Reservoir: An Example from the Wara Formation in the Greater Burgan Field

Dashti

Filak

Bond

et al. 2017

Day 1 Mon, October 09, 2017

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The Wara reservoir is one of the main producing formations of the giant Greater Burgan field. It has been on production under natural depletion for many years. A massive water-flood of this formation has recently commenced. This was preceded by a large-scale pilot water flood the aims of which included enhancing reservoir understanding. This paper describes how historical data, including data from the large-scale pilot, were used to construct representative part filed models. The area of the pilot water flood has significant volumes of data, including core and log data and dynamic data such as pressure transient data, interference tests, tracer tests and cased-hole logs. These provide valuable information for reservoir characterization. The Wara formation was deposited in a tidally influenced fluvio-deltaic environment where sand continuity is complex. There was a desire to develop realistic geological and simulation models that accounted for our understanding of Wara geology and were consistent with the large volumes of surveillance data. A major challenge was the choice of an appropriate area for the part field model. This was chosen so as to allow water influx into the area of interest over the life of the field to be accounted for and to allow relatively simple boundary conditions to be applied. Geological models were constructed using object based techniques. These models used reservoir rock types that were developed to broadly match permeability-height estimates from pressure transient data. The geological models were not guaranteed to account for the sand connectivity inferred form the surveillance data. A streamline based screening technique was used to exclude models that did not broadly capture the interpreted connectivity. Dynamic simulation models were then developed and conditioned to data using conventional assisted history matching techniques. At this stage, some sensitivities related to boundary conditions were explored. Sand connectivity was not varied at this stage. Some examples are given as to how the resulting conditioned models have been used to address questions about expected future reservoir performance. Specifically questions related to proposed well spacing and pattern type are discussed. This paper describes a novel approach to developing models that are geologically realistic and are consistent with the interpretation of reservoir connectivity from a range of surveillance data. This involves using a streamline based screening tool before using assisted history matching techniques. Such an approach can be applied to both part and full field models. The challenges of using such an approach with part field models are described. Some guidance is given to know when it would be appropriate to try to develop and condition part field models.

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Strategies for Improving Sweep Efficiency and Waterflood Recovery in a Complex Reservoir in the Greater Burgan Field; Learning from a Pilot Water Injection Project and Evaluation Using Sector Model Simulation

Cited by 2 publications

References 4 publications

Sector modeling using iterative boundary pressure estimation

Sector modeling using iterative boundary pressure estimation

A Novel Approach to Developing and Conditioning Part Field Models for a Complex Fluvio-Deltaic Reservoir: An Example from the Wara Formation in the Greater Burgan Field

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