ABSTRAKPenelitian identifikasi persebaran reservoir karbonat dilakukan pada Cekungan Jawa Tengah Utara Formasi Baturaja, yang didominasi oleh litologi batugamping. Tujuan dilakukan penelitian ini untuk mendapatkan nilai persebaran reservoir karbonat pada Formasi Baturaja dengan menggunakan metode atribut seismik amplitudo dan inversi impedansi akustik. Penggunaan metode tersebut mempermudah penulis untuk menganalisis keberadaan zona reservoir karbonat. Data yang digunakan yaitu data sumur, data seismik 2D PSTM, dan geologi. Metode atribut seismik yang digunakan dalam penelitian ini yaitu amplitudo root mean square (RMS), sedangkan metode inversi impedansi yang digunakan yaitu metode inversi model based. Nilai korelasi pada setiap sumur yang dihasilkan dalam proses pra-inversi sangat tinggi yaitu 0,9. Analisis atribut amplitudo root mean square (RMS) menunjukkan nilai persebaran reservoir karbonat berada di sebelah barat daya dan barat laut dari setiap sumur dengan kontras nilai amplitudo yang tinggi yaitu 3000 sampai 12000. Analisis inversi impedansi akustik model based menunjukkan bahwa persebaran reservoir karbonat pada Formasi Baturaja ditandai dengan nilai impedansi 18456 sampai 33689 (ft/s)*(gr/cc). Potensi hidrokarbon pada reservoir karbonat terdapat pada nilai impedansi yang relatif rendah yaitu 18456 sampai 27596 (ft/s)*(gr/cc).Kata kunci: Cekungan Jawa Tengah Utara, Formasi Baturaja, reservoir karbonat, atribut seismik, inversi impedansi akustik.ABSTRACTIdentification research of the carbonate spread reservoirs was carried out in the North Central Java Basin of the Baturaja Formation, which is dominated by limestone lithology. The purpose of this research was to obtain the distribution value of the carbonate reservoir in the Baturaja Formation by using the amplitude seismic attribute method and acoustic impedance inversion. The use of this method makes it easier for the authors to analyze the presence of a carbonate reservoir zone. The data used are well data, 2D PSTM seismic data, and geology. The seismic attribute method used in this study is the amplitude root mean square (RMS), while the impedance inversion method used is the model based inversion method. The correlation value for each well produced in the pre-inversion process was very high, namely 0.9. The root mean square (RMS) amplitude attribute analysis shows the value of the distribution of carbonate reservoirs in the southwest and northwest of each well with a high contrast amplitude value of 3000 to 12000. Model-based acoustic impedance inversion analysis shows that the distribution of carbonate reservoirs in the Baturaja Formation is marked with an impedance value of 18456 to 33689 (ft/s)*(gr/cc). The hydrocarbon potential in the carbonate reservoir is found at a relatively low impedance value, namely 18456 to 27596 (ft/s)*(gr/cc).Keywords: North Central Java Basin, Baturaja Formation, carbonate reservoir, seismic attributes, acoustic impedance inversio
