Pematang-Sihapas petroleum system of Central Sumatra
Conference
·
OSTI ID:425649
- Texaco Inc., Houston, TX (United States)
The Pematang - Sihapas (PAD) petroleum system of Central Sumatra is one of the most important lacustrine oil systems in Southeast Asia. The Brown Shale Formation (lacustrine) of the Pematang Group has sourced {approx}60 x 10{sup 9} BO. Reservoirs are developed within the uppermost Pematang Gp. (Paleogene) and superjacent Sihapas Group (Early Miocene). Sihapas sandstones are the principal reservoirs of this system. Giant fields (e.g., Minas and Dud) having Sihapas (marine sandstone) reservoirs occur principally along the eastern margins of the rift basins. Smaller fields having Pematang (nonmarine sandstone) reservoirs are confined to the rift basins. The Pematang Gp. was deposited in a series of small grabens. It exhibits a tripartite arrangement: basal (Lower Red Bed) fluvial/alluvial unit; medial (Brown Shale) lacustrine unit; and upper (Upper Red Bed) fluvial/alluvial unit. Source rock attributes of the Brown Shale are highly variable. Pyrolysis yields of samples containing {ge} 1.0 wt.% TOC range up to {approx}120 mg HC/g rock, with a mean of {approx}25.3 mg HC/g rock. Differences in kerogen reflect variations in preservation rather than organic input. The overlying Menggala Formation (basal transgressive unit of Sihapas Gp.) has an average porosity of >20 % and an average permeability of 1500 md. The amount of sandstone (gross) in the Menggala Fm. typically exceeds 50%. Menggala strata consist of well-sorted quartzose to subarkosic sandstones. Menggala sandstones are the most prolific hydrocarbon reservoirs in Central Sumatra. Many of the oil fields in Central Sumatra are associated with structures formed during a mid-Miocene compressional event.
- OSTI ID:
- 425649
- Report Number(s):
- CONF-960527--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Pematang-Sihapas petroleum system of Central Sumatra
Structural evolution of the Pematang Reservoirs, Kelabu-Jingga Gas Fields, Sumatra
Sedimentology and diagenesis of a rift basin lacustrine sandstone: Pematang group, central Sumatra, Indonesia
Conference
·
Sun Dec 31 23:00:00 EST 1995
· AAPG Bulletin
·
OSTI ID:6590790
Structural evolution of the Pematang Reservoirs, Kelabu-Jingga Gas Fields, Sumatra
Conference
·
Fri Jul 01 00:00:00 EDT 1994
· AAPG Bulletin (American Association of Petroleum Geologists); (United States)
·
OSTI ID:6726443
Sedimentology and diagenesis of a rift basin lacustrine sandstone: Pematang group, central Sumatra, Indonesia
Conference
·
Thu May 01 00:00:00 EDT 1986
· Am. Assoc. Pet. Geol., Bull.; (United States)
·
OSTI ID:5167232