Dalam usaha pengembangan lapangan minyak Rahma dan Nala penting untuk dilakukan pemodelan dan karakterisasi reservoir yang meliputi distribusi fasies dan properti reservoir batupasir 1950 dan 2110 Formasi Bekasap yang merupakan salah satu reservoir di lapangan ini. Hasil penelitian ini diharapkan dapat memberikan gambaran suatu play concept yang lebih baik dalam meningkatkan performance lapangan.Identifikasi distribusi fasies dan properti reservoir menggunakan metoda simulasi kondisional sekuensial yang merupakan salah satu metode geostatistik yang termasuk dalam kategori simulasi berbasis grid dengan mengintegrasikan beberapa data seperti data core, data sumur dan data seismik 2D.Berdasarkan analisa data core dan elektrofasies, daerah penelitian terdiri dari beberapa fasies pengendapan yakni fasies channel sand, fasies bar sand dan fasies marine shale dimana batupasir 1950 dan 2110 yang menjadi objek penelitian merupakan fasies channel sand.Akibat keterbatasan data maka geometri reservoir fasies channel sand tidak dapat diidentifikasi secara pasti. Untuk mengakomodasi ketidakpastian ini maka pemodelan dilakukan berdasarkan tiga skenario yang meliputi lebar dan ketebalan fasies channel sand serta arah pengendapan yang akan memberikan 23 realisasi model distribusi fasies. Dari beberapa realisasi model yang dihasilkan, akan di ranking dan diuji kebenarannya untuk mendekati kondisi geologi bawah permukaan yang sebenarnya.

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During the development program of Rahma and Nala fields, it is important to execute modeling and reservoir characterization that is comprised of reservoir properties and facies distribution. The program will focus on two potential reservoir in Bekasap Formation, they are 1950 and 2110 sandstone. The expectation from the evaluation result capability to describe a better play concept in order to increase fields performance.

Identification of reservoir properties and facies distribution in these fields will use Sequential Conditional Simulation. Sequential Conditional Simulation is one of geostatistical method which is categorized as grid base simulation that integrates several data such as core, well data and 2D seismic.

According to core and electrofacies analysis, the field can be differentiated into several depositional facies which are channel sand facies, bar sand facies and marine shale facies while 1950 and 2110 sandstone are known as channel sand facies. Reservoir geometry cannot be determined easily because of data limitation. To accommodate the uncertainty, the modeling was run by emphasizing 3 scenarios, such as width and thickness of channel sand and azimuth. The scenarios will produce 23 realizations of facies model distribution. All of them will be ranked and will be tested in order to approach real sub surface condition.