scholarly journals Overview of Lower Cretaceous Achimov Formation: Physical Properties and Their Distribution Pattern in West Siberian Basin, Russia

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mingyu He ◽  
Qingbin Xie ◽  
A. V. Lobusev ◽  
M. A. Lobusev ◽  
Xinping Liang
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Distribution Patterns ◽  
Burial Depth ◽  
Reservoir Properties ◽  
Reservoir Rocks ◽  
Oil And Gas Fields ◽  
Genetic Mechanisms ◽  
Gas Fields ◽  
West Siberian Basin

The Achimov Formation is one of the most important oil- and gas-bearing strata in the West Siberian basin in Russia. The total estimated reserves of this stratum exceed one billion tons. The formation was first explored in 1981, but it remains largely underdeveloped due to its deep burial depth and poor physical properties. Therefore, further research on the genetic mechanisms and distribution characteristics of the reservoirs in the formation can contribute to its further exploitation. The Achimov Formation is dominated by of fine- to medium-grained sandstones interbedded with shale. Based on analysis of well logging data, hand specimens, and previous research, this study analyzed the properties of three members (Ach1, Ach2, and Ach3) of the Achimov Formation and summarized their distribution patterns. Research on reservoir rocks from different oil and gas fields reveals varying physical properties across the formation with permeability and porosity increasing from the northern to central areas and decreasing from the central to the southern areas. Burial depth is one of the major controlling factors for reservoir properties in the formation. Reservoirs in both the northern and southern parts of the formation are buried deeper than those in the central areas, resulting in a disparity in reservoir quality.

Determining factors of the unconsolidated rocks of Cenomanian reservoir on the Bolshekhetskaya depression

2021 ◽  
pp. 57-68
Author(s):  
N. Yu. Moskalenkо
Keyword(s):  
Oil And Gas ◽  
The Arctic ◽  
Arctic Seas ◽  
Reservoir Rocks ◽  
Carbonate Cements ◽  
Oil And Gas Fields ◽  
Determining Factors ◽  
Thermobaric Conditions ◽  
Gas Fields ◽  
Hydrocarbon Reserves

The relevance of the article is associated with the importance of the object of the research. Dozens of unique and giant oil and gas fields, such as Urengoyskoye, Medvezhye, Yamburgskoye, Vyngapurovskoye, Messoyakhskoye, Nakhodkinskoye, Russkoye, have been identified within the Cenomanian complex. The main feature of Cenomanian rocks is their slow rock cementation. This leads to significant difficulties in core sampling and the following studies of it; that is the direct and most informative source of data on the composition and properties of rocks that create a geological section.The identification of the factors, which determine the slow rock cementation of reservoir rocks, allows establishing a certain order in sampling and laboratory core studies. Consequently, reliable data on the reservoir and estimation of hydrocarbon reserves both of discovered and exploited fields and newly discovered fields that are being developed on the territory of the Gydan peninsula and the Bolshekhetskaya depression will be obtained. This study is also important for the exploration and development of hydrocarbon resources of the continental shelf in the waters of the Arctic seas of Russia as one of the most promising areas.As a result of the analysis, it was found that the formation of rocks of the PK1-3 Cenomanian age of the Bolshekhetskaya depression happened under conditions of normal compaction of terrigenous sedimentary rocks that are located in the West Siberian basin. Slow rock cementation of reservoir rocks is associated with relatively low thermobaric conditions of their occurrence, as well as the low content of clay and absence of carbonate cements. Their lithological and petrophysical characteristics are close to the analogous Cenomanian deposits of the northern fields of Western Siberia and can be applied to other unconsolidated rocks studied areas.

scholarly journals Cretaceous Subsurface Geology of the Middle East Region

GeoArabia ◽  
1997 ◽  
Vol 2 (3) ◽  
pp. 239-256 ◽  
Author(s):  
Louis Christian
Keyword(s):  
Middle East ◽  
Lower Cretaceous ◽  
Oil And Gas ◽  
Regional Scale ◽  
Reservoir Rocks ◽  
Subsurface Geology ◽  
Oil And Gas Fields ◽  
East Region ◽  
Isopach Maps ◽  
Gas Fields

ABSTRACT A regional structure contour map at Near Top Cretaceous is based on hundreds of well tops from extensive bibliographic references from throughout the Middle East. This structure map shows strong basin asymmetry. Major faults are shown in outcrop and/or suspected at basement or intermediate levels, based in part on gravity and magnetics modeling, published and in ‘open file’ studies. Major uplifts associated with several super-giant oil and gas fields are clearly indicated even at the shallow Cretaceous level (Ghawar Anticline, Qatar Arch, Burgan-Khurais Trend, etc.), even at a very regional scale with a contour interval of 1,000 feet. Isopach maps of Upper, Middle, and Lower Cretaceous are contoured at intervals of 500 feet. Each of these three isopach maps is overprinted in color to show generalized lithofacies trends. Lower and Middle Cretaceous deltaic sandstone fairways on the western shelf provide excellent reservoir rocks for a trend containing many of the world’s very largest oil fields. Somewhat more basinward, predominantly carbonate facies include oil reservoirs in the Upper, Middle, and Lower Cretaceous. Deepest facies lie beneath the Zagros Foothills Belt in coastal Iran and eastern Iraq. This is particularly true for the Upper Cretaceous, where Coniacian to Maestrichtian thick, deep basinal shales, cherts, clastic turbidites, and slumped exotic blocks of ophiolites mark the northeastern border of the Late Cretaceous basin as it approaches the Main Zagros Fault and an assumed subduction zone underthrusting the Iranian Plate or Eurasia.

Comparative geological setting of conventional oil and gas fields and CSG resources in the Surat/Bowen Basin, Queensland

2009 ◽  
Vol 49 (2) ◽  
pp. 580
Author(s):  
Rob Willink
Keyword(s):  
Oil And Gas ◽  
Gas Content ◽  
Small Contribution ◽  
Coal Seams ◽  
Reservoir Properties ◽  
Oil And Gas Fields ◽  
The Difference ◽  
Permian Coal ◽  
Gas Fields ◽  
Coal Measures

The Surat/Bowen Basin has long been of interest to explorers in pursuit of gas and oil in conventional reservoirs. Some 500 BCF of gas and 32 million barrels of oil have been produced from sandstones of Permian, Triassic and Jurassic age. Geochemical evidence suggests that these hydrocarbons were sourced almost exclusively from Permian coal measures, though a small contribution from Triassic coals cannot be discounted. Primary interest in these basins today, however, resides in the exploration for, and commercialisation of, methane trapped in coal seams within the Permian and Jurassic successions. Total industry declared proven, probable and possible (3P) coal seam gas (CSG) reserves exceed 30 TCF, of which some 8 TCF are attributed to reserves in Permian coal seams, and 22 TCF in Jurassic coal seams. With particular reference to a representative regional seismic traverse through the basin, this presentation will explain why known conventional and CSG fields in these basins are located where they are from a regional structural and stratigraphic perspective. The difference between the reservoir properties of coals and sandstones, and between the Permian and Jurassic coals will be discussed in terms of their maceral composition, gas content, adsorption capacity and thermal maturity. In addition, the location of known sweetspots within CSG fairways will be revealed. The presentation will conclude with some speculative comments on what the future holds for both conventional and CSG exploration in these basins and will show that Origin Energy, in particular through its investment with Conoco Phillips in Australian Pacific LNG (APLNG), is well placed to participate in that future.

Sign in / Sign up

Export Citation Format

Share Document