Increasing well life cycle by eliminating the multistage Cementer and utilizing a Light Weight High Performance Slurry

Abstract Trapped gas and oil between production and intermediate casing (abnormal annulus wellhead pressure) has been globally recognized as one of the serious challenges facing drilling and production operations. The issue is becoming serious since wells are aging and the integrity of the casing portion below well head is increasingly affected by the shallow water corrosive environment. The potential safety and environmental hazards of the abnormal annulus pressure, have encouraged ADCO to review the current drilling and cementing practices, aiming at minimizing the impact of the problem, thus improving well life cycle and reducing the frequent work-over interventions. The general guide lines set to resolve the problem were by eliminating potential leakage paths in the completion and casing strings, and by emphasizing on the quality of the primary cementing, specially of the production casing string. Cementing casing in single stage utilizing lightweight slurries has been the technique used in ADCO to improve 9 5/8" primary cementing. The new cementing methods have been found operationally and economically feasible. Summary for the recent case histories are presented in this paper, along with the conclusions and recommendations.