Material Balance and Reservoir Compartmentalisation Analysis for The Mereenie Field in the Northern Territory
Le Anh Tu Nguyen, Truc Thanh Thi Nguyen and Jeiyang Wang - 2012
Australian School of Petroleum
University of Adelaide
This honour project is a study which combines compartmentalization analysis (with additional construction of pressure profiles) and material balance modelling (MBAL software) to current hydrocarbon production formations (Pacoota 1 and Pacoota 3) of Mereenie field. The outcome from this study is to validate the original oil in place (OOIP) and original gas in place (OGIP). This study is based on 30 years of production history and effectiveness of enhanced oil recovery scheme using reinjected gas which is coming from P1 gas production. In addition, understanding of the compartmentalization magnitude is a requirement for current implication of new drilling and production developments (MADD project) in Mereenie.
The compartmentalization analysis has successfully identified compartments with an obvious boundary indication across P1 and Eastern P3 formations. A conventional method of comparing fluid properties and pressure history as outlined from Jolley et al. (2010) is the basis of the compartment determination. The result from P1 gas material balance model is a validation of the initial model (established in 2007). Further three tanks were developed in the Far East region within the oil rim of P1. Meanwhile, P3 has in total 15 compartments, where fourteen compartments have been in production. In particular, tanks' boundaries within the East nose region have better interpreted.
From the implication of compartmentalization study, material balance models for both P1 and P3 formation were developed with variation in outcome. While P1 delivers a good match between simulation result and production history in gas cap with known OGIP of 181Bcf and oil rim with known OOIP of 17.5 MMstb, a better match was observed in West Mereenie than East Mereenie in P3. Shortcomings such as lack of PVT data in each defined regions has significantly contributed the variation between simulated and historical production. Under compartmentalization analysis results, six tanks divided equally between oil rim and gas cap were successfully modelled for P1. In P3, only 12 compartments were successfully modelled with known OOIP of 41.9 MMstb and OGIP of 23.3 Bcf. In addition, recommendation on Enhanced oil production scheme has been drawn out as a result of simulated material balance model for East regions of P3.