Publications

The Mahakam PSC is a mature oil and gas concession in the Mahakam Delta which has been producing for more than 40 years. More than 100 wells per year are drilled from deltaic to offshore production fields (Tunu, Tambora, Handil, Peciko, Bekapai, Sisi-Nubi, and South Mahakam). A total cumulative production of 19 TCF of gas and approximately 1.5 Billion barrels of oil have been produced since 1974. The Peak of Mahakam PSC production started from 2005 and the PSC has been facing natural decline from 2010 to the current date. Several strategies have been implemented to maintain the production rate, and one of them is unlocking less developed reservoirs in the deeper target. Overpressure is one of the challenges to reach the deeper target reservoir. Drilling in an overpressure zone often has serious and unpredictable outcomes. In addition, it has also been exacerbated by massive production in the main zone reservoirs for many years. This massive production has reduced reservoir pressure that led to the decreasing of fracture pressure. These two subsurface challenges effect the narrow window for drilling in the Mahakam operational area and it will certainly also affect the safety, cost and economics of the wells. So, optimizing pore pressure and fracture pressure predictions become the key to unlock less developed reservoirs in mature Mahakam fields. Pore Pressure and Fracture Pressure predictions are developed by understanding the geopressure concept, predicting pore pressure, estimating fracture pressure, developing 3D pore pressure model and performing reservoir distribution analysis. During 2019, eight challenging wells had been drilled and succeeded in unlocking 7.7 BCF of gas reserves. Besides that, Non Productive Time (NPT) of the well control is also decreased yearly and affects the well’s cost efficiency. The improvement of the methodology has been implemented comprehensively to support upcoming challenging exploration and is also expected to sustain the future development of mature Mahakam Fields.