Prediction and Localisation of Erosion Prone Areas along Non-Compliant Sand Control Completions

Abstract

Abstract Sandface completions such as standalone screen completions have suffered from erosion problems for many years. A significant amount of catastrophic screen failures are considered to be the result of high velocities of solid's laden hydrocarbons creating hot spot areas in the interface between the sandface and the completion. Previous researchers investigated the change in permeability of failed rock into annular gaps generated in non-compliant sand control completions and identified that packed material in this space can result in severe distortion to flow patterns and restrictions. This paper describes the development and testing process for a new methodology that allows identification of the erosion prone areas in the annular space between the sandface and the screen. Detailed investigation, supported by laboratory testing, reviewed oil and gas well conditions at the startup, during a cleanout and after hydrocarbon's production have been stabilised. Radial flow, mode of sand collapse, compaction, voidage, sand quality and formation petro-physical properties were tested and analysed using high and low pressure flow cells in order to quantify the changes in pressure drops through the collapsed rock material. The results indicated that flow rate, viscosity, voidage, grain shape and volume are the main contributors to the variations in pressure drops across failed sand material in the annular space. On the basis of these tests, a continuous (foot-by-foot) analytical model was developed that allows identification of the specific location and variation in pressure drops across the annular packed material for oil and gas wells. The model is composed of five (5) main elements; a reservoir inflow module, a fluid drag module, a grain size and volume module, a pressure drop module and an erosion prediction module. The model was tested using data from a North Sea field and the results, algorithms and field samples will be discussed and presented in detail.