Upscaling for improved oil recovery

Pinggang Zhang, Gillian Elizabeth Pickup, Michael Andrew Christie

    Research output: Contribution to conferencePaper

    Abstract

    Upscaling for the simulation of IOR processes is a big challenge, for several reasons. Firstly, the geological model may be complex, in order to resolve important structures, such as channels or shales, and to target remaining oil. Secondly, the recovery processes also tend to be complex, involving two-phase or three-phase flow. Careful flow simulation is therefore required to estimate oil recovery. Many upscaling methods have been developed to reduce the number of cells in a geological model, so that the models can be used for flow simulation. Inevitably, coarse-scale simulations are less accurate, especially in highly heterogeneous models. In the early stages of development of a field, this may not be important, because the reservoir model is highly uncertain. Later in the life of a reservoir, however, it is important to maintain the accuracy of flow simulation, especially when trying to predict the additional oil produced by IOR techniques. We present a method for upscaling which is suitable for use at the IOR stage of development of a reservoir. This method maintains a high accuracy compared with the fine-scale simulation, and is feasible for highly heterogeneous, multi-million cell models. We perform a single-phase pressure solution over the fine scale geological model, using well pressures and natural reservoir boundary conditions (e.g. high aquifer pressures, sealing faults), and calculate upscaled transmissibilities and well connection factors. This upscaling approach takes longer to run than conventional upscaling methods, which apply the boundary conditions locally to each coarse- scale cell. However, it has the advantage of avoiding errors due to inappropriate boundary conditions, and the effects of the main geological structures can thus be preserved. In addition, this method is quicker, more robust and more practical than dynamic two-phase upscaling. The method is demonstrated to have the capability of reproducing two-phase, and even three-phase (WAG) behaviour in the models tested.
    Original languageEnglish
    Pages30-37
    Number of pages8
    Publication statusPublished - Apr 2005
    Event13th European Symposium on Improved Oil Recovery 2005 - Budapest, Hungary
    Duration: 25 Apr 200527 Apr 2005

    Conference

    Conference13th European Symposium on Improved Oil Recovery 2005
    Abbreviated titleIOR 2005
    CountryHungary
    CityBudapest
    Period25/04/0527/04/05

    Fingerprint

    upscaling
    oil
    simulation
    boundary condition
    three phase flow
    pressure solution
    sealing
    geological structure
    method
    aquifer

    Cite this

    Zhang, P., Pickup, G. E., & Christie, M. A. (2005). Upscaling for improved oil recovery. 30-37. Paper presented at 13th European Symposium on Improved Oil Recovery 2005, Budapest, Hungary.
    Zhang, Pinggang ; Pickup, Gillian Elizabeth ; Christie, Michael Andrew. / Upscaling for improved oil recovery. Paper presented at 13th European Symposium on Improved Oil Recovery 2005, Budapest, Hungary.8 p.
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    title = "Upscaling for improved oil recovery",
    abstract = "Upscaling for the simulation of IOR processes is a big challenge, for several reasons. Firstly, the geological model may be complex, in order to resolve important structures, such as channels or shales, and to target remaining oil. Secondly, the recovery processes also tend to be complex, involving two-phase or three-phase flow. Careful flow simulation is therefore required to estimate oil recovery. Many upscaling methods have been developed to reduce the number of cells in a geological model, so that the models can be used for flow simulation. Inevitably, coarse-scale simulations are less accurate, especially in highly heterogeneous models. In the early stages of development of a field, this may not be important, because the reservoir model is highly uncertain. Later in the life of a reservoir, however, it is important to maintain the accuracy of flow simulation, especially when trying to predict the additional oil produced by IOR techniques. We present a method for upscaling which is suitable for use at the IOR stage of development of a reservoir. This method maintains a high accuracy compared with the fine-scale simulation, and is feasible for highly heterogeneous, multi-million cell models. We perform a single-phase pressure solution over the fine scale geological model, using well pressures and natural reservoir boundary conditions (e.g. high aquifer pressures, sealing faults), and calculate upscaled transmissibilities and well connection factors. This upscaling approach takes longer to run than conventional upscaling methods, which apply the boundary conditions locally to each coarse- scale cell. However, it has the advantage of avoiding errors due to inappropriate boundary conditions, and the effects of the main geological structures can thus be preserved. In addition, this method is quicker, more robust and more practical than dynamic two-phase upscaling. The method is demonstrated to have the capability of reproducing two-phase, and even three-phase (WAG) behaviour in the models tested.",
    author = "Pinggang Zhang and Pickup, {Gillian Elizabeth} and Christie, {Michael Andrew}",
    year = "2005",
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    language = "English",
    pages = "30--37",
    note = "13th European Symposium on Improved Oil Recovery 2005, IOR 2005 ; Conference date: 25-04-2005 Through 27-04-2005",

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    Zhang, P, Pickup, GE & Christie, MA 2005, 'Upscaling for improved oil recovery', Paper presented at 13th European Symposium on Improved Oil Recovery 2005, Budapest, Hungary, 25/04/05 - 27/04/05 pp. 30-37.

    Upscaling for improved oil recovery. / Zhang, Pinggang; Pickup, Gillian Elizabeth; Christie, Michael Andrew.

    2005. 30-37 Paper presented at 13th European Symposium on Improved Oil Recovery 2005, Budapest, Hungary.

    Research output: Contribution to conferencePaper

    TY - CONF

    T1 - Upscaling for improved oil recovery

    AU - Zhang, Pinggang

    AU - Pickup, Gillian Elizabeth

    AU - Christie, Michael Andrew

    PY - 2005/4

    Y1 - 2005/4

    N2 - Upscaling for the simulation of IOR processes is a big challenge, for several reasons. Firstly, the geological model may be complex, in order to resolve important structures, such as channels or shales, and to target remaining oil. Secondly, the recovery processes also tend to be complex, involving two-phase or three-phase flow. Careful flow simulation is therefore required to estimate oil recovery. Many upscaling methods have been developed to reduce the number of cells in a geological model, so that the models can be used for flow simulation. Inevitably, coarse-scale simulations are less accurate, especially in highly heterogeneous models. In the early stages of development of a field, this may not be important, because the reservoir model is highly uncertain. Later in the life of a reservoir, however, it is important to maintain the accuracy of flow simulation, especially when trying to predict the additional oil produced by IOR techniques. We present a method for upscaling which is suitable for use at the IOR stage of development of a reservoir. This method maintains a high accuracy compared with the fine-scale simulation, and is feasible for highly heterogeneous, multi-million cell models. We perform a single-phase pressure solution over the fine scale geological model, using well pressures and natural reservoir boundary conditions (e.g. high aquifer pressures, sealing faults), and calculate upscaled transmissibilities and well connection factors. This upscaling approach takes longer to run than conventional upscaling methods, which apply the boundary conditions locally to each coarse- scale cell. However, it has the advantage of avoiding errors due to inappropriate boundary conditions, and the effects of the main geological structures can thus be preserved. In addition, this method is quicker, more robust and more practical than dynamic two-phase upscaling. The method is demonstrated to have the capability of reproducing two-phase, and even three-phase (WAG) behaviour in the models tested.

    AB - Upscaling for the simulation of IOR processes is a big challenge, for several reasons. Firstly, the geological model may be complex, in order to resolve important structures, such as channels or shales, and to target remaining oil. Secondly, the recovery processes also tend to be complex, involving two-phase or three-phase flow. Careful flow simulation is therefore required to estimate oil recovery. Many upscaling methods have been developed to reduce the number of cells in a geological model, so that the models can be used for flow simulation. Inevitably, coarse-scale simulations are less accurate, especially in highly heterogeneous models. In the early stages of development of a field, this may not be important, because the reservoir model is highly uncertain. Later in the life of a reservoir, however, it is important to maintain the accuracy of flow simulation, especially when trying to predict the additional oil produced by IOR techniques. We present a method for upscaling which is suitable for use at the IOR stage of development of a reservoir. This method maintains a high accuracy compared with the fine-scale simulation, and is feasible for highly heterogeneous, multi-million cell models. We perform a single-phase pressure solution over the fine scale geological model, using well pressures and natural reservoir boundary conditions (e.g. high aquifer pressures, sealing faults), and calculate upscaled transmissibilities and well connection factors. This upscaling approach takes longer to run than conventional upscaling methods, which apply the boundary conditions locally to each coarse- scale cell. However, it has the advantage of avoiding errors due to inappropriate boundary conditions, and the effects of the main geological structures can thus be preserved. In addition, this method is quicker, more robust and more practical than dynamic two-phase upscaling. The method is demonstrated to have the capability of reproducing two-phase, and even three-phase (WAG) behaviour in the models tested.

    M3 - Paper

    SP - 30

    EP - 37

    ER -

    Zhang P, Pickup GE, Christie MA. Upscaling for improved oil recovery. 2005. Paper presented at 13th European Symposium on Improved Oil Recovery 2005, Budapest, Hungary.