Implementation of Stimulation Treatment for Gas-lift Well in Sirt Basin, Libya

Abstract

Many sources of formation damage exists which normally contribute to a reduction in well productivity by introducing an extra positive skin near the wellbore. The main objective of matrix stimulation treatment is to remove this damage. Such treatment was a new approach in Amal formation contained within Sirt basin. The challenge faced was the need to inject Break-Down Acid Job (BDAJ) technique without inducing fractures in the formation (safety margin bottom-hole pressure value should be not be exceeded), mean while, the formation was depleted and applying high injection rate was essential to ensure that the acid reaches the targeted zone. This paper details a combination of techniques, implemented in Sirt basin, which have proven to enhance the overall operations’ economics and well deliverability. Furthermore, the paper describes a novel approach for Gas Lift Analysis. A proper design was achieved following the proposed techniques resulting in a successful stimulation treatment. Certain measures were required to avoid causing any damage and to deal with unexpected events. The formation responded positively to the acid treatment. A significant increase in flow rate was observed indicating a successful treatment and that the well restored its natural undamaged inflow performance successfully. In this study a detailed economic impact was done to confidently prove the profitability of the treatment over the production life of the well. The results obtained from this case study suggest that several wells producing from Amal formation can benefit from the proposed new techniques.