INTEGRATED PRODUCTION-SYSTEM OPTIMIZATION FOR LATE-LIFE GAS-CONDENSATE FIELDS: COUPLING WELL DELIQUIFICATION, NEAR-WELLBORE REMEDIATION AND LOW-PRESSURE SURFACE OPERATION

Abstract

Mature gas-condensate fields commonly reach a stage at which production is no longer controlled by a single reservoir limitation. Declining reservoir pressure, retrograde condensate accumulation, positive near-wellbore skin, wellbore liquid loading, rising gathering-system backpressure, and insufficient compression capacity interact and can move a well from stable production to intermittent or fully loaded operation. This paper develops an integrated engineering workflow for screening late-life production options by coupling reservoir inflow, near-wellbore impairment, continuous liquid-removal criteria, tubing hydraulics, surface backpressure, and low-pressure compression. Five operating scenarios were compared: the existing system, surface compression only, velocity string combined with compression, selective near-wellbore remediation combined with compression, and a fully integrated bundle including gathering-system pressure reduction. The representative calculations increased stable gas rate from 42 to 76 thousand Sm³/d and raised the continuous-liquid-removal margin  from 0.78 to 1.67, while the required wellhead pressure was reduced from 3.2 to 1.35 MPa. The results show that compression or stimulation applied independently may recover only part of the available deliverability; the largest and most stable benefit occurs when reservoir, wellbore, and surface constraints are treated as a coupled system. A screening matrix is proposed for selecting interventions according to skin, liquid-loading margin, water/condensate influx, tubing friction, and compression availability. The workflow is intended for engineering diagnosis and option ranking before detailed compositional reservoir simulation, multiphase well modeling, and facility design.