Rapid Design of an Inflow Control Device Completion in Heterogeneous Clastic Reservoirs Using Type Curves

A near-uniform well (production) inflow or (injection) outflow profile delays early water breakthrough and further decreases water cut which results in higher oil recovery. Field experience has shown that wells producing from, or injecting into, multiple layers and/or reservoirs benefit from an Inflow Control Device (ICD) completion's ability to reduce the in/out-flow imbalance along its length. The standard ICD completion design workflow involves selection of the "strength" of the ICD's restriction based on the incomplete knowledge of the reservoir that is available prior to drilling the well with several commercial softwares available for this.

However, more complete reservoir data becomes available once the drilled completion zone has been logged and the data analysed. There follows a short period of time during which the engineer must judge whether the planned ICD completion design is "fit-for-purpose" or needs further consideration. The availability of a rapid ICD completion design methodology that does not require access to computationally demanding commercial software would be highly beneficial at this time.

This paper presents a workflow which meets the above requirements. It extends our previous analytical approach to ICD sizing to directly relate the uniform-strength ICD completion design to the predicted heterogeneity of the open-hole inflow profile together with the consequent loss in well productivity from the ICD's flow restriction. The workflow combines a series of dimensionless, universal type curves and analytical solutions in a relatively simple and fast process to find the desired ICD design. A new completion design can be made immediately after drilling has been completed to provide the desired level of inflow variation from the latest predicted level of reservoir and fluid inflow heterogeneity determined by a "quick-look" evaluation of the well's log data. The same design procedure can be used to select ICD completion designs that are a compromise between two competing objectives: increasing the uniformity of the inflow profile and minimising the reduction of the well's productivity index that results from the extra pressure losses imposed by the ICDs.

Two typical examples of the workflow's application are provided. The first one examines whether it is necessary to change the ICD completion design when drilling problems result in a reduction of the well's completion length. The second example evaluates the impact of the actual reservoir permeability profile being more heterogeneous than originally expected. The workflow's design philosophy was confirmed by commercial numerical simulators recommending the same ICD completion design in both cases.

This work extends our earlier analytical approach to ICD sizing. This new ICD completion design workflow can be used by completion design engineers to rapidly analyse uniform-strength ICD completion design options and their consequences on well inflow performance without expensive computational resources. The underlying principles, assumptions and application area of the analytical model are fully discussed in the paper.