Publications

Handil is a mature oil field located on the internal axis of the Mahakam delta Shelf with a less developed shallow section. One of the shallow reservoirs, referred here as reservoir A, has a very good productivity, however it experienced a very fast decline due to massive water breakthrough which came unexpectedly. There was uncertainty in hydrocarbon volume in-place lead by uncertainty in contact & reservoir boundaries. In addition to that, the production data was very limited (~4 months production, coming from only 1 well), thus there are limited production data to understand the reservoir behavior. A Pressure Build-Up (PBU) test was then carried out to better understand reservoir boundaries, in place & productivity. Dynamic simulation was performed in order to have a better understanding on reservoir behavior and in place. It was also expected to optimize infill wells scenario based on dynamic simulation result. During History-Matching (HM), PBU result was utilized as a reference. Sensitivity of volume in place was performed as a part of HM. In forecast stage, sweetspot was determined using Simulation Opportunity Index (SOI). During HM, several scenarios of volume in place and well productivity were trialed. Besides matching on well production profile, the PBU and derivative were also matched. Significant differences of PBU response can be seen between Low in Place Case and Best in Place Case, thus make the history match process becoming more efficient. The study revealed that combining PBU data and dynamic reservoir simulation was an excellent methodology to tackle uncertainty in this reservoir since its solution is more unique compared to well production profile matching only. PBU Derivative Match then leads to help identify the suitable Geomodel (OOIP).