Analytical Approach to Investigate the Factors Influencing Sand Production from Deviated Well
Engineering Honours Degree, 2006
University of Adelaide
Sand production posses a critical problem in oil and gas industries worldwide. While sand occurrence have been variously reported in industry, ample of researches have been conducted to study the principle causes of sand production. Due to the complexity that lies behind sand occurrence, and problems due to sand control operation such as productivity impairments and excessive maintenance of both downhole and surface equipments , many have choose to deal with sand production in a more sophisticated way termed the Sand Management. Flow restriction by controlling the following bottom hole pressure or reservoir pressure drawdown has been reported in many occasion as one of the successful Sand Management approaches especially in the early life of the well.
In this study an analytical model has been developed based on flow restriction approach to investigate the effects of wellbore orientation with respect to the direction of maximum horizontal in-situ stress and prevailing stress regimes on the onset of sand production from deviated well through sensitivity analysis. The onset of sand production has been predicted based on both the wellbore flowing bottom hole pressure and reservoir pressure drawdown. Depending on the critical values of these pressures, the risk of sand production can be minimized by reducing the tendency for failure around the wellbore in the early life of the well and maintain production from the well under conditions not subject to failure.
These studies have demonstrated that the risk of sand production can be minimized by controlling the wellbore flowing pressure and/or pressure drawdown based on early analysis for deviated wells. It is also found that these pressures are significantly influenced by the well orientation with respect to the maximum horizontal stress direction and prevailing insitu stress regimes.
Thus, it is hoped that this model is useful in addressing sanding issues at an early stages allowing a review of different option of wellbore orientation and developing an optimum and most economical production strategy.