Located about 50 km from the nearest commercial city in East Malaysia, lies an old exploration gas well that was drilled and abandoned in 1952. This well, identified as well Orange 1, was observed to be leaking by a housing developer company in 2013 as they were progressively constructing houses in that area. This resulted in temporarily suspension of the construction works in fear of potential harmful gas leakage and explosion.
The well Orange 1 is a high pressure exploration gas well that was drilled to about 12,000 feet and immediately abandoned back in 1952. Given that this well was never opened to production, the reabandonment design had to be done based on the well still having the virgin reservoir pressure with the potential of flowing up to 7000 psi. This alone imposed several technical and operational challenges which requires lengthy and detail engineering approach. The reabandonment in many ways simulated drilling into a shallow gas zone. There was limited information available regarding the well and the original cement plugs were neither checked for depth nor tested during the original abandonment and their very existence was based on the number of sacks of cement reported to have been pumped in the drilling reports. It was theoretically possible to drill through the top 200feet cement plug and find full reservoir pressure at surface, so equipment and procedures had to be in place to accommodate the worst case scenario. Since this well was in the vicinity of a housing area, additional public risk and logistical challenges also had to be managed to ensure the deliverables are achieved in the safest manner.
This paper outlines the overall integrated project management process to evaluate all the down hole and surface risks, environment, public interest and logistical challenges and its related planning, solutions, risks management and lessons learnt from the 6 months execution phase. As this is the first land well reabandonment in Malaysia, it has now become a reference and benchmark for any near future land well reabandonment works. Together with the service sector, PETRONAS also carried out design and operation optimization process to even further enhance the execution.