High gas and sand production along with productivity decline are amongst some common well management challenges in oil producers of Azeri-Chirag-Gunashli (ACG) field in the Azerbaijan sector of the Caspian Sea. This paper will focus on trials in the region in deploying chemical treatments to tackle excessive gas and sand production in unconsolidated reservoirs.
Sand production can disrupt normal operations at topside facilities, cause well management challenges and well productivity impairment. Successful sand shut-off (SSO) also means reduction of some financial and safety impacts for the business.
Reservoir pressure support through secondary recovery mechanisms is an important component for delivering production targets of ACG field. With continuation of gas injection for reservoir pressure support, the Gas Oil Contact (GOC) can move closer to the producers at times resulting in well management challenges due to rising well Gas Oil Ratios (GORs). Upon free gas breakthrough (GBT), well drawdowns are actively restricted to prevent further growth in gas rate and subsequent acceleration of oil rate decline. For some wells, an effective Gas Shut-Off (GSO) would mean immediate production impact associated with increased drawdown available potential. In others, the driver for GSO is the need to minimize total facility gas production volumes to avoid immediate or future production deferrals due to gas facility constraints. In sand producing wells, successful GSO interventions provide the secondary benefit of reducing risk of flow-line and choke erosion that arise during well life.
Various mechanical and chemical techniques have been assessed and deployed in trials to mitigate high gas and sand production in ACG over the last four years. The objective of this paper is to share the candidate selection methodology and results of the chemical GSO and SSO trials implemented to date. In addition to this overview, the surveillance data supporting the candidate selection process will be presented with pre and post intervention well parameters to demonstrate the impact of the shut-off techniques along with longevity.