Method of Surface Interception To Access Annulus With Abnormal Gas Pressure

One of the operator’s newly acquired ventures is in the North field offshore Qatar. Abnormal rise in Annuli C and D pressures during the last phase of drilling highlighted the need to investigate the condition of producing wells on other platforms. The chances of inner annuli becoming charged with shallow-gas pressure and possible communication to Annulus D was thought to be a well-integrity concern. Establishing safe access to the sealed and potentially gas-charged Annulus D thus posed a challenge.

Introduction

The North field is offshore northeast of Qatar and is the world’s largest nonassociated-gas field.