Exploring in Asia, Africa and the Americas for oil & gas in naturally fractured basement reservoirs: best practices & lessons learned

Basement rocks are important oil and gas reservoirs in a number of basins in the world. The basement oil and gas play has intensified in the past decade with significant basement discoveries. This paper provides a technical review of select basement oil and gas fields in Asia, Africa and the Americas. “Best practices” for exploring and developing basement fields are reviewed. Failures are also considered since basement reservoirs can be very complicated and unpredictable. Preference scale for basement reservoir rock types is presented. The opinion of this author is that the best rock types are fractured quartzites or granites since they are brittle and thus fracture optimally. Based on international experience, recommendations on the study of crystalline basement for oil and gas and the development of deposits in it are given.

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Map of Texas showing oil and gas fields, pipelines, and areas of exposed basement rocks

10.3133/om214 ◽

1964 ◽

Keyword(s):

Oil And Gas ◽

Oil And Gas Fields ◽

Basement Rocks ◽

Gas Fields

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HYDROCARBON HABITAT OF THE SURAT/BOWEN BASIN

The APPEA Journal ◽

10.1071/aj81017 ◽

1982 ◽

Vol 22 (1) ◽

pp. 213 ◽

Cited By ~ 1

Author(s):

B. M. Thomas ◽

D. G. Osborne ◽

A. J. Wright

Keyword(s):

Oil And Gas ◽

Lower Jurassic ◽

Source Rocks ◽

Lateral Migration ◽

Early Maturity ◽

Oil And Gas Fields ◽

Basement Rocks ◽

Origin Of Oil ◽

Gas Fields ◽

Geochemical Studies

Ever since the early discoveries at Cabawin (1960) and Moonie (1961), the origin of oil and gas in the Surat/Bowen Basin has been a subject of speculation. Hydrocarbons have been found in reservoirs ranging in age from Permian to Early Jurassic; even fractured pre-Permian 'basement' rocks have occasionally recorded shows.Recent geochemical studies have identified rich source rocks within the Jurassic, Triassic and Permian sequences. The Middle Jurassic Walloon Coal Measures are thermally immature throughout the Surat Basin and are unlikely to have generated significant amounts of hydrocarbons. Lower Jurassic Evergreen Formation source rocks have reached 'nominal early maturity' (VR = 0.6) in parts of the basin. The Middle Triassic Moolayember Formation lies within the oil generation zone in the northern Taroom Trough. However, no oil has yet been confidently correlated with either a Jurassic or a Triassic source. On geochemical and geological grounds it is likely that most, if not all, of the hydrocarbons discovered to date were generated from Permian source rocks.The probability of finding gas as well as oil in Permian, Triassic or Jurassic reservoirs increases from south to north, in accord with organic maturity trends in the Permian of the Taroom Trough. On the narrow thrust-bounded eastern flank, vertical migration has occurred, resulting in oilfields at Moonie and Bennett. In contrast, extensive lateral migration of hydrocarbons across the gentle western flank of the basin is indicated by numerous small oil and gas fields on the Roma Shelf and Wunger Ridge.

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Giant and major-size oil and gas fields worldwide in basement reservoirs: state-of-the-art and future prospects

Georesursy ◽

10.18599/grs.2020.si.40-48 ◽

2020 ◽

pp. 40-48

Author(s):

Tako Koning

Keyword(s):

Oil And Gas ◽

State Of The Art ◽

Reservoir Engineering ◽

Future Prospects ◽

Economic Data ◽

The Past ◽

Oil And Gas Fields ◽

Basement Reservoirs ◽

Giant Size ◽

Gas Fields

Oil and gas occurs in basement reservoirs in many parts of the world. The reserves of basement fields are as small as one or two million barrels of oil or gas-equivalent such as the Beruk Northeast pool in Sumatra, Indonesia to over 1.0 billion barrels of oil as in Viet Nam’s Bach Ho field and Libya’s Augila-Naafora field. This paper focuses on three giant-size oil and gas fields and six major-size fields. Exploration for oil and gas in basement has been remarkably successful in the past decade with important discoveries in basement in Indonesia, United Kingdom, Norway, Chad, and Argentina. In order to successfully develop basement oil and gas fields and also to avoid costly mistakes, all available geological, geophysical, reservoir engineering and economic data must be closely studied. Also, it is very important to study analogues worldwide of basement oil and gas fields in order to understand why some fields are very successful and others turn out to be technical and economic failures.

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Mathematical modeling and investigation of anomalies of the temperature field of the earth′s crust over oil and gas reservoirs

Physico-mathematical modelling and informational technologies ◽

10.15407/fmmit2020.28.092 ◽

2019 ◽

pp. 92-101

Author(s):

Mykhailo Semerak ◽

Hanna Lyantse

Keyword(s):

Temperature Field ◽

Oil And Gas ◽

Earth’S Crust ◽

Temperature Fields ◽

Gas Reservoirs ◽

Neutral Layer ◽

Oil And Gas Fields ◽

Oil And Gas Reservoirs ◽

Earth's Crust ◽

Gas Fields

In geothermal studies of oil and gas fields, temperature anomalies were found in the surface layers of the crust. In the paper, mathematical models of temperature fields of the Earth's crust over the oil and gas reservoirs have been constructed. The anomalies of the temperature field in the neutral layer depending on the depth of deposits, the capacity of the reservoir have been investigated using experimental data. A mathematical model of the Earth's crust has been also constructed taking into account its lithological structure. The influence of lithological heterogeneity of the layer on the temperature fields in the neutral layer has been investigated.

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An Integrated Approach to Map Tubular Degradation in ONWJ Field

Proc. Indon. Petrol. Assoc., Digital Technical Conference, 2020 ◽

10.29118/ipa20-e-278 ◽

2020 ◽

Author(s):

F. Sajjad

Keyword(s):

Oil And Gas ◽

Field Performance ◽

Integrated Approach ◽

Lessons Learned ◽

Oil And Gas Fields ◽

Preventive Actions ◽

Infill Drilling ◽

Actual Field ◽

And Performance ◽

Gas Fields

Tubular engineering is essential for production operations, especially in mature oil and gas fields. The complex interaction between hydrocarbon and non-hydrocarbon components will eventually result in tubulars deteriorating into poor condition and performance. 1500 well examples are located in field X, Indonesia, in which 70% of them have been producing for more than 30 years, indicating the existence of tubular thinning and deformation. The degradation is slowly developed until severe alterations are observed on the tubing body. The situation from the aforementioned wells is complicated since tubular deformation inhibits the flow as well as increasing the risk of wellbore collapse and complications during sidetracking, infill drilling, workover, and other production enhancement measures. These wells are subjected to costly remedial measures and often result in unsuccessful recovery efforts. The authors present the degree of tubular degradation and its effect to overall field performance and the possibility of tubular failure. Current field practices do not encourage a thorough tubular assessment during early life of the wells, which create complex problems at a later stage. Eventually, the study indicates that proper planning and preventive actions should be performed gradually before tubular degradation becomes severe. This paper presents a field experience-based model that is useful in developing new areas from the perspective of well and facilities integrity, so that the degradation-related issues can be recognized earlier. We used multiple case studies with actual field data to identify the dominant mechanism for tubular degradation. The case study presented a model that is capable to describe the extent of tubular degradation in offshore, mature wells that are prone to stress from its surroundings. Lessons learned from these failures encourages us to conduct a comprehensive study on tubular degradation. It is performed to model the incorporation of multiple degradation mechanisms on tubular performance.

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Stratigraphy, Tectonics and Hydrocarbon Habitat of the Abadan Plain Basin: A Geological Review of a Prolific Middle Eastern Hydrocarbon Province

Geosciences ◽

10.3390/geosciences8120496 ◽

2018 ◽

Vol 8 (12) ◽

pp. 496 ◽

Cited By ~ 2

Author(s):

Vahid Atashbari ◽

Mark Tingay ◽

Khalid Amrouch

Keyword(s):

Oil And Gas ◽

Middle Eastern ◽

Wellbore Stability ◽

Gas Reservoirs ◽

Dezful Embayment ◽

Petroleum Systems ◽

Oil And Gas Fields ◽

The Persian Gulf ◽

Stability Issues ◽

Gas Fields

The Abadan Plain Basin is located in the Middle East region which is host to some of the world’s largest oil and gas fields around the Persian Gulf. This basin is a foredeep basin to the southwest of the Zagros Fold-Thrust-Belt, bounded along its northern and eastern margins by the Dezful Embayment. Most of the rocks in this basin have been deposited in a carbonate environment, and existing fractures have made the formations a favourable place for hydrocarbon accumulations. The basin is enriched by oil and, therefore, gas reservoirs are few, and some of the explored reservoirs exhibit significant degrees of overpressure. This paper has compiled several aspects of the Abadan Plain Basin tectonics, structural geology and petroleum systems to provide a better understanding of the opportunities and risks of development activities in this region. In addition to the existing knowledge, this paper provides a basin-wide examination of pore pressure, vertical stress, temperature gradient, and wellbore stability issues.

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Risk-Based Screening Level Analysis and Landfill "Cap" Design of Crude Oil Contaminated Soil Stockpile in Riau Province, Indonesia

International Journal of Environmental Science and Development ◽

10.18178/ijesd.2021.12.2.1316 ◽

2021 ◽

Vol 12 (2) ◽

pp. 42-50

Author(s):

I Made Wahyu Widyarsana ◽

◽

Sukandar ◽

Windy Chyntia Dewi

Keyword(s):

Best Practices ◽

Crude Oil ◽

Contaminated Soils ◽

Oil And Gas ◽

Base Layer ◽

Technical Approach ◽

Government Regulations ◽

Oil And Gas Fields ◽

Gas Fields ◽

Level Analysis

In this study, a crude-oil contaminated stockpile is analyzed to understand the health risks and technical approach in its remediation. The stockpile has an approximate area of 13 hectares, with an approximate volume of 1.300.000 m3. Relaxed government regulations regarding environmental protection up in 2014 have made stockpiling crude-oil contaminated soils commonplace in Indonesia's oil and gas fields. The stockpile has a flat-shaped landscape, sloping at approximately 10 to 15 degrees, with a varied elevation ranging from 29 meters to 31 meters, peaking at 31.5 meters. This study's objective was to correctly identify the best curative approach to remediate the location to adhere to the Indonesian Government standards and best practices. A landfill "cap" aims to treat the hazardous waste stockpile similar to a typical landfill, though with the absence of the base layer below the stockpile.

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Variation of density with rock type, depth, and formation in the Western Canada basin from density logs

Geophysics ◽

10.1190/1.1441107 ◽

1980 ◽

Vol 45 (6) ◽

pp. 1061-1076 ◽

Cited By ~ 22

Author(s):

J. Maxant

Keyword(s):

Oil And Gas ◽

Average Density ◽

Canada Basin ◽

Western Canada ◽

Frequency Distributions ◽

Depth Functions ◽

Rock Types ◽

Oil And Gas Fields ◽

Level Of Significance ◽

Gas Fields

Gamma‐gamma logs were used to study the density of sedimentary rocks and formations in the Western Canada basin. The frequency distributions of density of all the main rock types have negative skewness, a characteristic that seems to be a general feature of density distributions of rocks based on well logging. The frequency distributions of density for sandstone and limestone were not found to be different from those of shale and dolomite, respectively, at the 0.01 level of significance. Several density‐depth functions were applied to the shale samples. Athy's (1930) exponential function provided the best fit to observed values. Using this function, the average thickness of sediments removed by denudation in south and central Alberta was calculated to be 4400 or 3600 ft on the assumption that the density of the original surface clay was 1.4 or [Formula: see text], respectively. Maps of average density for six formations in Alberta and Saskatchewan indicate only a partial correlation with lithology and depth. A large scattering of density with depth was found in the case of four Cretaceous formations in which density was observed to be independent of the sandstone/shale ratio. In the case of one formation containing predominantly shale, no obvious dependence on depth was found. Also, no relationship between density and the occurrence of oil and gas fields was apparent.

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