Real Time Choke Erosion Prediction Using Real-Time Advisory Tool

Abstract

Abstract Wellhead choke valve is commonly used to control flow rate in production and injection wells in oil industry. Wells producing high solids content can cause erosion resulting in production loss and potential safety concerns due to choke failure. In such cases continuous choke valve monitoring has become crucial to detect issues at the onset. In this paper, a well digital twin was developed to monitor choke erosion and predict when it might happen. An advisory tool was developed to monitor choke valve erosion in offshore High Pressure High Temperature (HPHT) offshore gas wells. The tool uses real-time surface wellhead parameters and choke correlations using industry standard steady-state production engineering design application to identify any anomalies in choke valve performance on real-time basis. The tool also provides a quantitative estimation of the chokes mean time to failure under actual production conditions which would open the way for improved design and increased life-span. Ten thousand data points were used for wells completed in gas reservoirs. The tool identified the start of erosion each time as it started until the choke was replaced in the selected wells over 7-year period with an accuracy of greater than 95%. The methodology provides a choke erosion indicator which compares actual and calculated choke size where a positive value gives the signal of choke erosion events as they start to happen. The results enable engineers and operators to avail the replacement of chokes in a period of three to five months where it took more than a year prior to the tool development. Moreover, the analysis further highlighted the safe rates to limit the erosion and how much time and production rate it shall take for the choke to erode once the erosion starts. The developed tool has aided in minimizing the safety related issues and risk of production loss due to choke failure. Additionally, it has also helped the engineers in making timely decisions by identifying the onset of erosion leading to better management of the material lead time for replacements. It is deemed to be useful not only to minimize production deferment but also mitigate any safety related issues and manage the procurement of long lead items especially in offshore fields.