| Popis: |
Gas lift design and optimization contributes to one of the key focus areas of whole production optimization value chain. There have been numerous methods and best practices which goes into design of a successful Gas Lift well as well as established industry best practices for the optimal operations of wells and network (facilities), but still gas lift designs derived for present or future well conditions, fail to respond to every possible operating scenario and end up multipointing, slugging or sub-optimal orifice injections. Well completion and well Integrity are two other important focus areas which are independent from gas lift design but possess major challenges to any gas lift well. During completion of a gas lift well, traditionally GLM (Gas Lift Mandrels) carrying dummy valves are run in hole, to allow for setting packers and testing the tubing/annulus strings. These dummy valves require numerous slickline operations to be retrieved and replaced with live IPO (Injection Pressure Operated) and orifice valves, to be able to gas lift. Depending on the well completion complexity (depth, deviation) and number of gas lift valves, slickline operations performed via rig or barge may require up to 3-5 field days. Since GLV replacement operation requires the use of kick over tools, they are susceptible to incur heavy NPT's and associated HSE risks (Slickline and wireline operations accounts for major carbon footprints in upstream segment). During gas lift operations, high pressure gas injected into casing possess enormous risks to nearby wells and surface facilities in the event of uncontrolled annulus gas leak from a single barrier envelope. Operating a gas lift well below MAASP (Maximum Allowable Annuus Surface Pressure) remains a challenge in assuring the well is operating within its integral envelope. At times it also leads to deferred production should the well needs suspended production in the event of SAP (Sustainable Annulus Pressure) or workover caused by compromised well integrity. In this technical paper, authors will attempt to provide a holistic view of a successful Gas Lift well design by addressing the challenges raised (as above) in different phases and emphasizing on the design approach and technical solutions which were implemented, and benefits realized in terms of optimal gas lift operations, rig/ barge days and deferred production saved. |
