[ABSTRAK
Aplikasi atribut seismik 3D dan sifat fisik batuan telah dapat memodelkan reservoar AFormasi Ledok Lapangan X Blok Cepu. Beberapa atribut seismik yang sesuai untukmengidentifikasi penyebaran reservoar dilapangan ini adalah root mean square (rms),sweetness, dan impedansi akustik relatif. Dimana ketiga atribut seismik tersebutmemperlihatkan suatu anomali amplitudo berupa bright spot yang diidentifikasi sebagaireservoar A dan memperlihatkan pola penyebaran berarah selatan-utara. Fasies reservoarA yang merupakan batugamping pasiran adalah reservoar yang sangat baik dalammenyimpan hidrokarbon gas dengan porositas 19% dan saturasi air sebesar 40%. Adanyafaktor ketidakpastian dalam penentuan batas penyebaran reservoar A dari atribut seismik,model reservoar A di bagi menjadi tiga bagian yaitu perkiraan optimis (P90), perkiraansedang (P50) dan perkiraan pesimis (P10). Keberadaan hidrokarbon gas di Lapangan Xdikontrol oleh suatu perangkap stratigrafi bukan perangkap struktur hal ini terlihat daritidak adanya tutupan (klosur). Berdasarkan sebaran reservoar melalui integrasi atributseismik, properti batuan dan model reservoar diusulkan 4 (empat) sumur pemboran untukmengembangkan lapangan gas X.

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ABTRACT
Application of 3D seismic attributes and physical properties of reservoir rocks have been tomodel the formation Ledok A Field X Cepu Block. The seismic attributes, which can be usedto identify distribution of the reservoir in this field were the root mean square (rms),sweetness, and relative acoustic impedance. The attributes of the seismic amplitude anomalyshows a bright spot in the form identified as reservoars A and show the pattern of northsouthtrending deployment. A reservoir facies which is a sandy limestone reservoir was verygood at keeping a hydrocarbon gas with 19% porosity and water saturation of 40%. Theexistence of uncertainty in the determination of reservoir distribution limit of seismicattributes. A reservoir model was divided into three parts, optimistic estimate (P90),moderate estimate (P50) and pesimistic estimate (P10). The existence of hydrocarbon gasesin field X in was control by a stratigraphic traps compared to traps structure as seen fromthe absence of cover (closur). Based on integration of seismic attributes, rock properties andreservoar model proposed four (4) wells drilling to develop the gas field X.;Application of 3D seismic attributes and physical properties of reservoir rocks have been tomodel the formation Ledok A Field X Cepu Block. The seismic attributes, which can be usedto identify distribution of the reservoir in this field were the root mean square (rms),sweetness, and relative acoustic impedance. The attributes of the seismic amplitude anomalyshows a bright spot in the form identified as reservoars A and show the pattern of northsouthtrending deployment. A reservoir facies which is a sandy limestone reservoir was verygood at keeping a hydrocarbon gas with 19% porosity and water saturation of 40%. Theexistence of uncertainty in the determination of reservoir distribution limit of seismicattributes. A reservoir model was divided into three parts, optimistic estimate (P90),moderate estimate (P50) and pesimistic estimate (P10). The existence of hydrocarbon gasesin field X in was control by a stratigraphic traps compared to traps structure as seen fromthe absence of cover (closur). Based on integration of seismic attributes, rock properties andreservoar model proposed four (4) wells drilling to develop the gas field X.;Application of 3D seismic attributes and physical properties of reservoir rocks have been tomodel the formation Ledok A Field X Cepu Block. The seismic attributes, which can be usedto identify distribution of the reservoir in this field were the root mean square (rms),sweetness, and relative acoustic impedance. The attributes of the seismic amplitude anomalyshows a bright spot in the form identified as reservoars A and show the pattern of northsouthtrending deployment. A reservoir facies which is a sandy limestone reservoir was verygood at keeping a hydrocarbon gas with 19% porosity and water saturation of 40%. Theexistence of uncertainty in the determination of reservoir distribution limit of seismicattributes. A reservoir model was divided into three parts, optimistic estimate (P90),moderate estimate (P50) and pesimistic estimate (P10). The existence of hydrocarbon gasesin field X in was control by a stratigraphic traps compared to traps structure as seen fromthe absence of cover (closur). Based on integration of seismic attributes, rock properties andreservoar model proposed four (4) wells drilling to develop the gas field X., Application of 3D seismic attributes and physical properties of reservoir rocks have been tomodel the formation Ledok A Field X Cepu Block. The seismic attributes, which can be usedto identify distribution of the reservoir in this field were the root mean square (rms),sweetness, and relative acoustic impedance. The attributes of the seismic amplitude anomalyshows a bright spot in the form identified as reservoars A and show the pattern of northsouthtrending deployment. A reservoir facies which is a sandy limestone reservoir was verygood at keeping a hydrocarbon gas with 19% porosity and water saturation of 40%. Theexistence of uncertainty in the determination of reservoir distribution limit of seismicattributes. A reservoir model was divided into three parts, optimistic estimate (P90),moderate estimate (P50) and pesimistic estimate (P10). The existence of hydrocarbon gasesin field X in was control by a stratigraphic traps compared to traps structure as seen fromthe absence of cover (closur). Based on integration of seismic attributes, rock properties andreservoar model proposed four (4) wells drilling to develop the gas field X.]