Successful Classical Production Optimisation Approach to Prolong the Field Life by Means of Well Cycling and Well Rocking in Extremely High Water Cut Gas Wells – A Case Study in Offshore Malaysia

"M" carbonate gas field in central Luconia province, offshore, Sarawak, Malaysia has been on production since 1995. The field is at the end of its life and all the gas producers scattered around the field are watered out having water cuts more than 95%. One of the main issues currently faced by reservoir management team is the prediction and handling of extremely high water breakthroughs at the existing producers. This paper outlines the basic and simple ways on how the team maximise the recovery from wells nearing end of life whilst minimising the cost of replacing water handling facilities at surface by adopting an approach of converting one of deepest gas producer well into Water Disposal Well (WDW), brought in the technique of well cycling and use of well rocking– method of unloading a well with other well. The field observed an early water breakthrough than expected and thus producing high amount of water. Since then the water imposes threats to gas production and water handling facilities. To cope with this issue various measures were taken. Team then proposes the efficient approach of well cycling, when gas rates decline, conversion of one of gas producer, deepest in formation, to be the WDW to facilitate the water production that is currently at 95% and then using the "well-rocking" for well unloading. The contribution from above techniques has proven an incremental reserves of 8% from existing wells with minimal additional cost. After the successful implementation and results of above programme, same has been applied to another nearby field which has proven the same results. The paper summarises the main issue of early water breakthrough and an effort to prolong the field production and results of converting gas producer to WDW, implications of cyclic production and their results, monitoring and example from two (2) fields.