A study using field and laboratory measurements to predict sand production for a multi-field gas development in offshore Peninsular Malaysia was carried out. Formation depths ranged from 1225 to 2450 metres with most of these fields having high CO2 and H2S content. Laboratory-derived properties were correlated with the openhole logs while the magnitudes of the in-situ stresses and formation pressure were derived from analysis of openhole logs, standard leak-off test data, coefficient of active earth pressure and qualitative stress information relating to the in-situ stress regime.
The sand production prediction model was calibrated against laboratory perforation collapse tests. The effect of well inclination/orientation, perforation orientation, reservoir pressure depletion and water-cut on sand production potential was evaluated. As downhole sand control increases well cost significantly and impairs well productivity, an assessment of the likelihood of sand production to decide if sand control is necessary and the timing of installation becomes very critical.
Sand production was found to be not a problem in the early part of the production of the fields with high reservoir pressures and low water-cut. Two over-pressured formations may have sand production problem with declining reservoir pressures. Based on the results of the study and expected reservoir pressures, drawdown and water-cut behavior of the fields, downhole sand control will not be required in the early stage of production.
This paper described the work done, techniques used, impact of the results of the study on the field development and benefits gained from the study.