Search Repository STTMIGAS Balikpapan

Cadangan produksi adalah perkiraan volume hidrokarbon (minyak, kondesat dan gas
alam) yang secara komersial dapat diambil dari volume hidrokarbon yang terakumulasi di
reservoir dengan metode operasi yang ada dan bersifat ekonomis. Cadangan dapat ditindak
lanjuti untuk dihitung apabila telah memenuhi beberapa kriteria, antara lain adalah telah
diketemukan (discovered), dapat diambil (recoverable), memenuhi syarat komersialitas
(commercial) dan adanya sejumlah volume yang tersisa (remaining).
Salah satu upaya untuk meramalkan cadangan produksi minyak bumi di masa depan
adalah dengan menerapkan metode decline curve. Metode decline curve merupakan salah satu
metode untuk memperkirakan besarnya cadangan minyak berdasarkan data-data produksi
setelah selang waktu tertentu. Fungsi analisa decline curve antara lain : mengetahui batas waktu
akhir produksi yang bernilai ekonomis, jumlah produksi pada titik batas economic limit, serta
mengetahui cadangan sisa dengan mengevaluasi sejarah produksi.
Hasil perhitungan dari perbandingan 3 jenis metode decline curve yaitu exponential
decline, hyperbolic decline dan harmonic decline, didapatkan nilai estimated ultimate recovery
(EUR) dengan metode exponential decline sebesar 586,384.28 bbl, dengan metode hyperbolic
decline sebesar 321,322.26 bbl sedangkan yang dihitung dengan metode harmonic decline
sebesar 300,250.97 bbl; nilai estimated remaining reserves (ERR) yang dihitung dengan metode
exponential decline sebesar 323,258.98 bbl, dengan metode hyperbolic decline sebesar
58,196.96 bbl dan dengan metode harmonic decline sebesar 37,125.67 bbl; nilai economic limit
dari 3 metode tersebut, memiliki qlimit yang sama sebesar 119.24 b/d; nilai life time production
dengan metode exponential decline selama 225.52 bulan atau 18.79 tahun, dengan metode
hyperbolic decline selama 190.28 bulan atau 15.86 tahun sedangkan yang dihitung dengan
metode harmonic decline selama 202.76 bulan atau 16.90 tahun.
Serta nilai recovery factor (RF) yang dihitung dengan metode exponential decline
sebesar 18.84%, dengan metode hyperbolic decline sebesar 10.32% dan dengan metode
harmonic decline sebesar 9.64%.

Production reserves are approximate volumes of hydrocarbons (oil, condensate and
natural gas) that can be commercially derived from accumulated hydrocarbon volumes in
reservoirs with existing and economical operating methods. The reserves can be followed up to
be calculated if they meet several criteria, such as discovered, recoverable, commercial eligible
and any remaining volume.
One attempt to forecast future oil production reserves is to apply the decline curve
method. Decline curve method is one method to estimate the amount of oil reserves based on
production data after a certain time interval. Decline curve analysis functions include: knowing
the end time of production of economic value, the amount of production at the limit point of
economic limit, and know the remaining reserves by evaluating the production history.
The results of the comparison are 3 types of methods decline curve is exponential
decline, hyperbolic decline and harmonic decline, obtained the value of the estimated ultimate
recovery (EUR) by the method of exponential decline amounted to 586,384.28 bbl, with the
method of hyperbolic decline amounted to 321,322.26 bbl whereas that calculated by the method
of harmonic decline of 300,250.97 bbl; value estimated remaining reserves (ERR) which is
calculated by the method of 323,258.98 bbl exponential decline, with the decline amounted to
58,196.96 hyperbolic method and the method of harmonic bbl decline amounted to 37,125.67
bbl; limit the economic value of the three methods, has the same qlimit of 119.24 b/d; life time
value of production by the method of exponential decline over 225.52 a month or 18.79 years,
with the method of hyperbolic decline over 190.28 months or 15.86 years, while that calculated
by the method of harmonic decline for 202.76 months or 16.90 years.
And the value recovery factor (RF) were calculated by the method of 18.84% exponential
decline, with the decline of 10.32% hyperbolic method and the method of harmonic decline of
9.64%.