Abstract
As an oil field depletes, stress and pressure change in the reservoir. Water and gas breakthrough are also expected to occur. These increase sand production propensity, limit production rates and bring forward the abandonment of the field. This paper presents a sand production case study for a mature oil field offshore Malaysia. The field has been on production for more than 20 years, and an infill drilling program was recently initiated. Sand production risk for the planned horizontal wells in this mature field was a concern for the program. The objective of the study reported in this paper was to quantify sanding risks and recommend sandface completion options for the planned horizontal wells.
An integrated workflow was applied to the study, encompassing mechanical earth modeling, sand production model development and validation, and prediction of sand production propensity for the planned wells. Relevant wireline logs were utilized to derive formation mechanical properties which were calibrated with laboratory-measured values. Leakoff tests and borehole breakout information were utilized to constrain horizontal stress magnitudes. Sand production model was developed and validated based on sand production experienced in the field to date. Sand production risks were assessed for the planned horizontal wells with various completion options. Sand production propensity, presented as critical drawdown pressure was established for all the reservoir formations. It was concluded that sand production risks exist for most of the completion scenarios studied, and downhole sand control would be needed. The study provides a solid basis to optimize sandface completion for the planned wells.
