ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00726.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00727.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The Talara Basin is an unusual forearc basin, inasmuch as it displays many features which are not characteristic of such a tectonic context. These features apparently result from the basin's location at the intersection of the Amazonas Aulacogen, the Andean orogenic belt, and the subduction zone of the Peru‐Chile Trench. The history of the Talara forearc basin is dominated by exlensional rather than compressional tectonic activity, which reached a peak after the Eocene in association with low‐angle gravity slides. This tectonism began with a prolonged synsedimentary phase, which, during the Paleocene‐Eocene, generated a complex system of horsts and grabens bounded by major high‐angle normal faults trending NE‐SW and NW‐SE. Closely related to repeated phases of uplift and erosion in the eastern Andean source areas, this structural pattern controlled unusually thick and coarse clastic sedimentation during the Paleocene‐Eocene; a thickness of about 22,000 ft has been preserved, from which volcanics are essentially absent.The depositional environments were a series of interfering, transverse and longitudinal, deltaic and submarine fan systems, all of which contain distal portions in which organic‐rich marine shales were deposited. Given these conditions, it is not surprising that the Talara Basin has produced to date more than a billion (109) barrels of oil. Although oil is produced from these depositional systems both on‐ and offshore, the latter environment has been barely explored near the present‐day coastline, and is believed to have enormous potential for

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00728.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The thermal maturity and source‐rock potential of the sedimentary succession in the Drake field, Melville Island, Arctic Canada, have been studied using reflected‐light microscopy and Rock‐Eval pyrolysis. The Mesozoic sediments are immature to mature (% Ro = 0.35‐0.80). Vitrinite reflectance in Cretaceous sediments ranges from 0.35 to 0.56%; in Jurassic sediments, it ranges from 0.40 to 0.66%, and in Triassic sediments, from 0.50 to 0.80%. The Triassic Schei Point Group shales and siltstones contain organic matter of marine origin, whereas the predominantly plant‐derived organic matter present in the Jameson Bay, Ringnes and Deer Bay Formations has higher TOC. Among the Schei Point Group sediments, the Eden Bay Member of the Hoyle Bay Formation has high TOC content (approx. 5.0%) and high HI values (in excess of 600 mg HC/g Corg). It is followed by the Cape Richards Member and the Cape Caledonia Member of the Murray Harbour Formation (approx. 5.0% TOC).Regional variations in the level of thermal maturity of Mesozoic sediments in the Sverdrup Basin are mainly a function of burial depth. Thermal subsidence, uplift, erosion and heat associated with periods of diapiric and igneous intrusions may have been responsible for the thermal maturity pattern in the Drake field. The Jurassic Jameson Bay, Ringnes and Deer Bay Formations are immature to marginally mature, and have limited oil‐generation potential due to their high terrestrial input. The organic matter is these formations has good ga

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00729.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Detailed petrologic, sedimentologic and geohistory analyses have been carried out on the Neocomian (Lower Cretaceous) Shurijeh Formation in the eastern part of the Kopet‐Dagh Basin, NE Iran. The results of these analyses show that the diagenetic history of Shurijeh sandstones was affected by their depositional settings, and the subsequent subsidence of these units through meteoric and compactional hydrologic regimes in this part of the Kopet‐Dagh Basin. These rocks consist mostly of sub‐litharenitic redbeds deposited during a regressive phase of sedimentation dominated by rapid siliciclastic sediment supply. The lower and middle portions of the interval studied were deposited in low‐sinuosity braided fluvial systems, and the upper portion was deposited in high‐sinuosity meandering systems.The porous and permeable sand‐rich units were partially filled by infiltrated clays, and early calcite, anhydrite and silica cements as they subsided through the meteoric regime. In the compactional regime, feldspars altered to clays, dolomite replaced calcite and penetrated authigenic silica, and a late‐stage of calcite cementation and replacement took place. These diagenetic events were followed by partial dissolution of early and late‐stage calcite cements that created secondary porosity in the sandstone units. During the late Miocene—early Pliocene (approximately 10 million years), the Late Alpine Orogeny resulted in the formation of structural traps in the Shurijeh Formation of the Sarakhs area. This was followed by migration of gas into the porous units of this formation, accounting for the Khangiran and Gonbadli gasfields.Relationships revealed in this study can be used to develop diagenetic models that will help predict diagenetic styles in dominantly non‐marine sandstones in other basins similar to the

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00730.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Rock‐Eval and coal analytical data are compared for New Zealand coal samples ranging from peat to medium‐volatile bituminous coal. Most are humic coals within the New Zealand coal band, which is representative of the Type III maturation series defined for kerogens. However, four were chosen as particularly high‐hydrogen coal types. Relations between individual parameters — principally H/C, O/C, Tmax, HI and OI — are generally similar to those of Espitalié et al. (1985, 1986), but important differences include a broader range of HI values in the peats and lignites, and a differentiation between maturation and coal‐type effects in the relationship of HI to H/C. Correlations of the effects of maturation on HI, OI, Tmaxand vitrinite reflectance are made by the use of the independent Rank(S) scale of Suggate (1959).Rank(S)/reflectance relations vary between well sequences. The Rank(S) scale is used to integrate biomarker data on hydrocarbon generation and expulsion. The oil zone (“oil window”) corresponds to the range of bituminous coals, beginning at Rank(S) 10 (Tmax425°C) and ending at Rank(S) 17 (Tmaxestimated at 550°C). Release of oil begins at or soon after Rank(S) 12.5 (Tmax435°C), and culminates in the range Rank(S) 14.5‐ 15.5 (Tmax460–480°C). For the Taranaki Basin, New Zealand, the results imply that a substantially greater volume of coal measures has been subject to oil generation and migration processes

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00731.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Core description and petrographic analyses were utilized to study East Slovakian Basin sandstone reservoirs. Reservoir development is largely dependent on the original sandstone composition, which is influenced by deposition in a deltaic setting, local sourcing and volcanic activity. Sandstones are texturally and mineralogically immature lithic and feldspathic arenites. The presence of unstable lithic grains and feldspars contributes to low, irregular reservoir porosity, due to deformation by compaction, and susceptibility to chemical alteration. Reservoir quality is also influenced by the subsequent diagenesis of the sandstones, which is driven by high heat flow. Lithic fragments and feldspars alter readily to form authigenic/diagenetic mineral suites, which tend to occlude porosity; however, dissolution of some of these grains also enhances secondary porosity development. Most observed porosity in the basin sandstones is secondary, developing from dissolution of both carbonate cement and unstable framework grains. Porosities suggest a weak decreasing trend with depth of burial. However, detailed examination of several localities reveals that porosity development is strongly influenced by local factors (e.g. structural evolution, sandstone lithology, and the distribution of volcanics). Sandstones of the East Slovakian Basin are generally not good hydrocarbon reservoirs (particularly for liquid hydrocarbons), due to the presence of unstable framework grains, early carbonate cementation and authigenic/diagenetic mineral suites. Exceptions are found when dissolution of cement and framework grains results in significant secondary porosity.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00732.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The Junggar Basin is an important oil‐ and gas‐bearing basin, with thick source rocks, of Carboniferous. Permian. Triassic and Jurassic ages. Hydrocarbon accumulations are controlled by major faults which trend NNW. NW and NE; NE‐striking reverse faults constitute the Kelemay thrust‐zone in the NW basin margin; those trending NW are of lesser importance; and those trending NNW on the southern basin margin control the formation of en echelon anticlines (Kuang, 1989), which are important sites of hydrocarbon accumu

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00733.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00734.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1993.tb00735.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY