The Longwangmiao (LM) gas field in southwest China features high-pressure (HP; approximately 75–76 MPa), high-temperature (HT; approximately 144–156°C), and high-production-rate (approximately 700 000–1 million m3/d) characteristics. Serious well-integrity problems were encountered in the development process. Wellhead growth was present in 33 wells, and four wells exhibited gas leakage through wellhead valves. A well-integrity-management system was developed based on annulus-pressure-management technology, wellhead-growth-risk analysis and control, downhole leakage detection, and wellhead corrosion and erosion detection, ensuring the safe and stable production of gas wells.
Introduction
In the four wells that experienced gas leakage after well completion, this mainly consisted of damage to and leakage of the wellhead valve stem seal, tail rod, and flange connection (Fig.
