Determining the Minimum Critical Transport Rate for Successful HzOHGPs with Brine

Abstract The industry has deployed long horizontal gravel packs for more than three decades. Early HzOHGPs were deployed with completion brine, which encountered challenges with reactive shale. More recently, shunted screens have [1] become the preferred design, allowing continuous packing in the event of shale collapse. In fields where shale reactivity can be managed with the appropriate drilling fluids and completion brines, brine packs remain a cost-effective and operationally simple alternative. Maintaining circulation rates above a minimum transport threshold is crucial in brine packing to prevent premature sand out. Below this threshold, dune height increases rapidly, causing the open hole to bridge off and obstruct sand placement down hole of the bridge. Most commercial gravel pack simulation software limits the minimum slurry rate by setting a maximum alpha bed height. This method ignores the interdependence between the dimensions of the bottom hole assembly, the open hole size, the gravel and carrier fluid properties, and the slurry gravel/proppant concentration. In the early 2000's, Shell developed a workflow to account for many of these factors and performed laboratory tests to provide data needed for the workflow. Calibrated by numerous lab tests and field data, this model has proven to be a key enabler for successful HzOHGP with brine. Since 2020, this workflow was expanded to include light weight proppant, which was used to achieve full alpha packs in ultralow margin (50-100psi) reservoirs[3][4]. This paper describes the workflow for estimating the bed height, the flowing pressure gradient along the open hole, and most importantly, the minimum possible slurry rate that accounts for the interdependence of these factors.