Sand production remains a key technical challenge in the ACG (Azeri-Chirag-Gunashli) field as the target formation is comprised of weakly consolidated sandstone. Although sand control completions (such as open hole gravel pack) are used to limit sand entry into the well, water breakthrough, increased fines production, high flux across completed intervals amongst other factors may negatively impact on their effectiveness as well as stability of reservoir rocks, resulting in high sand production, consequently requiring choking back of wells. This, at times, leads to significant production deferrals, which are attributed to the impact on entire production system: completion, wellbore, chokes, flow lines and production vessels. Therefore, improving techniques and developing technologies for downhole diagnostic and remediation to restore production will be of value throughout the ACG field life. An effective remediation requires an understanding of the sand entry points. Over the last 24 months, BP has developed a new real-time technology solution that employs novel signal processing techniques using Distributed Acoustic Sensing (DAS) systems to detect sand entry points along the wellbore during production. The technology solution has been employed to the interpretation of over 30 conducted surveys to identify sand entry zones in real time. In some instances, the results have also been used to inform targeted remediation using expandable patches.
This paper summarizes the results from some of the DAS sand detection surveillance data acquired (in integration with other relevant dataset) and its use in remediation of compromised completion intervals. The authors will also share examples of drawdown optimization and risk management of wells with sand production based on acquired DAS data. This paper will cover a few examples of DAS survey data acquired both for wells with pre-installed fibre (25 wells) and those without it where the technology was deployed via wireline intervention (5 wells). The application of DAS technology in ACG has provided substantial value to date (both in terms of production and safety) and has much more value to be realized as the technology continues to mature.