Large Oil Fields Research Articles

A Study on the Relationship between Oil Micro-occurrence State and Oil Source in Low Permeability Tight Sandstone Reservoir Based on Computer Technology - a Case Study of Daqing Oilfield

Well logging is a method of measuring earth parameters using a variety of geophysical properties. In oil fields, it is often referred to as field geophysical exploration, petroleum and mineral geophysical or geophysical logging. The use of logging technology can reduce the workload of drilling and coring, improve the exploration speed and reduce the cost of exploration, so it is widely used in oilfield development activities. This paper takes Daqing oilfield, the largest oilfield in China since 1960s, located in the middle of songliao plain, as an example, and analyzes the application of logging method based on computer technology in oilfield development.

Application Research of Big Data Analysis Technology in Oil and Gas Field Development

The goal of oil and gas field development is to maximize the benefits of exploitation work. In some large oilfields entering the mid-to-late development stage, to maximize the input-output ratio of oilfield exploitation, in oilfield development work, you will receive Due to the influence of many interference factors, in the field of oilfield exploitation, it is necessary to reduce the economic cost of oil and gas field exploitation as much as possible and continuously improve the economic benefits of oilfield mining units. In the mid-to-late production of oil and gas fields, the use of big data to establish a reasonable and scientific production plan for oil fields and an effective decision support system provide an important guarantee for the development and production of oil and gas fields in the middle and late stages. Through the use of effective production-increasing technology and production decision-making, comprehensively consider some oilfield mining areas and newly-added resource mining areas, comprehensively optimize and set up the development of oilfield resources in the middle and late stages and use big data technology to develop oilfields. Among them, the resource advantages are effectively transformed into economic advantages, in order to provide a good work plan for the middle and late stages of oilfield development.

Reservoir formation conditions and key technologies for exploration and development in Qingcheng large oilfield

The Qingcheng oilfield, the largest shale oil field in China, was discovered in 2019 in source rock of Chang 7 Member of Mesozoic Yanchang Formation, Changqing Oilfield in Ordos Basin, with newly increased proven geological reserves of 358 million tons, predicted geological reserves of 693 million tons, and a total of 1.051 billion tons of shale oil resources. This achieves a historic breakthrough in exploration of shale oil in Chang 7 Member. In recent years, focusing on key issues, such as whether there develop sweet spots in source rock, whether commercial oil production capacity can be formed, and whether scale-effective development can be achieved, studies about geological conditions for shale oil accumulation have been continuously carried out, key supporting technologies have been developed, and a series of theoretical innovations and technological breakthroughs have been achieved in oil exploration in source rocks. The results indicate that shale oil accumulation in Chang 7 Member is controlled by following factors. Firstly, lacustrine black shale, dark mudstone and other high-quality source rocks lay a material foundation for shale oil formation. Secondly, sandy deposits intercalated within black shale and dark mudstones are exploration sweet spots, and sandbody combination types are controlled by morphology of bottom of the lacustrine basin. Thirdly, reservoir properties are good due to development of micro-nano pore throats. Finally, reservoirs with high oil saturation and high gas-oil ratio are formed due to high-intensity oil charging in source rock. Effective matching of multiple factors is a key for shale oil accumulation in Chang 7 Member in Ordos Basin. Through innovation of key supporting technologies, exploration and development technologies for shale oil are developed, and substantial breakthrough on exploration and development of shale oil is realized. The first application of logging-seismic combination technology in loess plateau improves significantly quality of 3D seismic data, which effectively guides prediction of sandy sweet spots. Three-quality well logging technology is used for further evaluation of geological and engineering sweet spots of shale oil. With volumetric fracturing technology based on precise segmentation of long horizontal wells, initial daily oil production of individual well is increased from previously 10 tons to more than 18 tons. The exploration breakthrough in source rocks in Chang 7 Member in Qingcheng oilfield provides an important resource base for the second accelerated development of Changqing Oilfield. It is predicated that oil production from shale in Chang 7 Member in Qingcheng oilfield will reach three million tons in 2022 and five million tons in 2025.

Discussion on the Application of EOR Technology in Oil Field

The driving technology of tertiary oil recovery is a higher-level oil recovery technology based on primary and secondary oil recovery technology, which is an important technology to fully exploit oil resources. Compared with the secondary oil recovery technology, the tertiary oil recovery and displacement technology is a great leap in the field of technology, which will greatly improve the efficiency of oil recovery and displacement. Tertiary oil recovery technology is based on the dual effect of physical reaction and chemical reaction, which will better exploit oil and natural resources. At present, the EOR technology has been applied to many large oil fields, which has become a perfect production technology. Through the tertiary oil recovery technology, the production efficiency of the oilfield has been improved by one third. Firstly, this paper analyzes the working principle of tertiary oil recovery technology. Then, this paper analyzes the application of EOR technology.

Male‐biased Demand Shocks and Women's Labour Force Participation: Evidence from Large Oil Field Discoveries

Do male‐biased labour demand shocks affect women's labour market outcomes? To study this question, we examine large oil field discoveries in the southern USA from 1900 to 1940. We find that oil wealth has an overall positive effect on female labour force participation that is driven by single women. While oil discoveries increase demand for male labour and raise male wages, they do not drive women out of the tradable goods sector or the labour force. Our findings suggest that the absence of any crowding out effects of oil wealth can be explained by compensating forces such as demand effects within the tradable sector, or by income effects that lead to growth in the non‐tradable sector.

E&P Notes (March 2020)

E&P Notes (March 2020)

Case study: Seismic resolution and reservoir characterization of thin sands using multiattribute analysis and bandwidth extension in the Daqing field, China

The Daqing field, located in the Songliao Basin in northeastern China, is the largest oil field in China. Most production in the Daqing field comes from seismically thin sand bodies with thicknesses between 1 and 15 m. Thus, it is not usually possible to resolve Daqing reservoirs using only conventional seismic data. We have evaluated the effectiveness of seismic multiattribute analysis of bandwidth extended data in resolving and making inferences about these thin layers. Multiattribute analysis uses statistical methods or neural networks to find relationships between well data and seismic attributes to predict some physical property of the earth. This multiattribute analysis was applied separately to conventional seismic data and seismic data that were spectrally broadened using sparse-layer inversion because this inversion method usually increases the vertical resolution of the seismic. Porosity volumes were generated using target porosity logs and conventional seismic attributes, and isofrequency volumes were obtained by spectral decomposition. The resulting resolution, statistical significance, and accuracy in the determination of layer properties were higher for the predictions made using the spectrally broadened volume.

Chapter 1 Introduction to the Jurassic Arabian Intrashelf Basin

Abstract The Jurassic Arabian Intrashelf Basin provides the setting for the world's greatest conventional oil reserves, including the world's largest oilfield, the supergiant Ghawar field. The stratigraphic interval corresponding to the development and infill of the Arabian Intrashelf Basin is from the uppermost Dhruma Formation to the top of the Hith Anhydrite Formation, spanning the late Bathonian–early Callovian to Tithonian. Many areas of the intrashelf basin have been well described in recent years and the stratigraphic succession has been defined in sequence concepts, but the regional development of the intrashelf basin has not been well synthesized. This Memoir builds on published data to give a regional interpretation of the geological evolution of the Arabian Intrashelf Basin. This introductory chapter reviews some of the earlier work, summarizes the key events and elements in the geological history of the Arabian Intrashelf Basin and gives a brief review of the history of petroleum exploration in this region. It is intended to serve as an extended abstract to introduce the general setting and summarize the contents of this Memoir, including some of the proposed revisions of depositional models, correlations and the sequence nomenclature, providing a context for considering and evaluating each subsequent chapter. The themes summarized in this chapter are documented and discussed in much greater detail in the subsequent chapters of this Memoir.

The Forties Field, Blocks 21/10 and 22/6a, UK North Sea

Abstract The Forties Field, discovered by BP in 1970, is the largest oilfield on the UK Continental Shelf. It is trapped in a simple four-way dip closure, with a Paleocene turbidite sandstone reservoir. The Forties Field originally contained between 4.2 and 5 billion bbl of oil, with 2.75 billion bbl produced to June 2017. Production has been supported by water injection and the influx of a regional aquifer. The original development contained equally spaced producers with peripheral injectors. As the field matured, production was concentrated in the crestal parts of the field with injectors tending to be moved upflank. With the development of seismic lithology prediction and fluid detection, together with 4D seismic technology, it became possible in the late 1990s to target bypassed oil in unexpected locations throughout the field. In 2003, BP sold the field to Apache who were able to rejuvenate production, adding over 170 MMbbl oil reserves, with an extended drilling campaign targeting bypassed pay identified using seismic technologies. Production at the Forties facility has been further enhanced by the development of four satellite oilfields, Bacchus (Jurassic reservoir), Brimmond, Maule and Tonto (Eocene reservoirs), together with Aviat (Pleistocene reservoir) produced for fuel gas supply.

Using NMR, Core Analysis, and Well Logging Data to Predict Permeability of Carbonate Reservoirs: a Case Study

Fluid flow through porous media is a function of permeability for petroleum and gas reservoirs. This study investigated the distribution of permeability in the Mishrif formation in the Nasiriya oilfield. The value of effective porosity was obtained from well log data and used to predict permeability using three methods: applied empirical correlations using interactive Petrophysics (IP) software (Version 3.5), core data measurements, and nuclear magnetic resonance (NMR). Nasiriya oil field is one of the large oil fields in southern Iraq, and the Mishrif formation, the area of the case study, consists of the following units from top to bottom: a cap rocks unit; the Upper Mishrif (unit 1); a shale unit; the first reservoir unit (2), a Barrier rocks unit; and the second reservoir unit (3). A 3D model was built by using Petrel software (2009), and the LAS files used to digitize the contour map of the reservoir layers were obtained from Didger3 software. The total number of 3D grids in the model was 5,394,480, with 336 grids in the I direction, 169 in the J direction and 95 in the k direction. Scaling up was done by using the geometric method for permeability, and sequential Gaussian simulation was used in the distribution of petrophysical properties. The results of distribution showed the importance of each zone and the best permeability value was recorded in the second reservoir layer, which varied from 1 md to 100 md.

Distribution Characteristics and Main Controlling Factors of Oil and Gas in the Bohai Sea Area

Liu, Y.; Cao, Q., and Zhang, Q., 2019. Distribution characteristics and main controlling factors of oil and gas in the Bohai Sea area. In: Li, L.; Wan, X., and Huang, X. (eds.), Recent Developments in Practices and Research on Coastal Regions: Transportation, Environment and Economy. Journal of Coastal Research, Special Issue No. 98, pp. 243–246. Coconut Creek (Florida), ISSN 0749-0208.In the Bohai Sea, structural oil and gas reservoirs account for the highest proportion of proven oil and gas reserves, followed by composite oil and gas reservoirs. In large and medium-sized oil and gas fields, which account for one-third of the total oil and gas fields, the proven oil and gas reserves account for 83% of the total reserves. Low uplift, middle sag uplift, and uplift structural belts have the most proven oil and gas reserves. Vertically, more than half of the proven oil and gas reserves are concentrated in the Neogene strata. More than 90% of the proven oil reserves and 85% of the proven gas reserves are distributed in shallow-middle reservoirs less than 3,000 M. The distribution of oil and gas in the Bohai Sea is the result of the interaction of a series of geological processes, such as source rocks, sedimentary systems, tectonic and fault systems development, and evolution. Oil and gas migrate and accumulate in short distance around hydrocarbon-rich sags; favorable sedimentary facies belts, high-quality lithofacies, and good physical properties determine the development of high-quality reservoirs in the Bohai Sea.

Application of technology of acoustic low frequency exploration for exploration and development of small oil fields in Udmurt Republic

Currently at the territory of the Udmurt Republic there is a depletion of previously discovered large oil fields. The increase in oil reserves is many times behind production. This problem can be solved by the introduction of oil fields with reserves of up to 300 thousand tons of oil. However the classical methods of prospecting, exploration and development makes identification and exploitation of these deposits economically not cost-effective. This problem can be solved by using the technology of acoustic low-frequency exploration at the search and evaluation and exploration stages of exploration. The forecasting scheme of hydrocarbon potencial of Debesskoe, Vostochno-Tylovaiskoe fields, as well as Staroaleiskaya and Marinskaya structures, studied by this method, has been shown. Advantages of application of technology of acoustic low-frequency investigation at carrying out the prospecting and exploration works on oil in the Udmurt Republic have been presented. The most promising geological structures to predict oil deposits by means of acoustic low frequency exploration in the territory of the Udmurt Republic have been suggested.

Spatiotemporal Analysis and Control of Landscape Eco-Security at the Urban Fringe in Shrinking Resource Cities: A Case Study in Daqing, China.

As the main bearing area of the ecological crisis in resource-rich cities, it is essential for the urban fringe to enhance regional ecological security during a city’s transformation. This paper takes Daqing City, the largest oilfield in China’s cold land, as an example. Based on remote sensing image data from 1980 to 2017, we use the DPSIR (Driving forces, Pressure, State, Impact, Response) framework and spatial auto-correlation analysis methods to assess and analyze the landscape eco-security change of the study area. From the perspective of time–space, the study area is partitioned, and control strategies are proposed. The results demonstrate that: (1) The landscape eco-security changes are mainly affected by oilfield exploitation and ecological protection policies; the index declined in 1980–2000 and increased in 2000–2017. (2) The landscape eco-security index has obvious spatial clustering characteristics, and the oil field is the main area of warning. (3) The study area determined the protection area of 1692.07 km2, the risk restoration area of 979.64 km2, and proposed partition control strategies. The results are expected to provide new decision-making ideas in order to develop land use management and ecological plans for the management of Daqing and other resource shrinking cities.

Reclamation of damaged agricultural land: an example of the Samara region

The issues of environmental protection, prevention of degradation and reclamation of damaged land are currently very significant and relevant. As damaged land has been observed the land where low productivity and low economic potential have arisen and natural productivity of ecosystems is changed due to human-caused activities. The nature and extent of the violation depends on the type, depth and duration of anthropogenic impact, on adopted system of work organization and the conditions of the environment. Black soil dominates in the soil cover in Samara region, therefore there has been developed agricultural production. However there are located large oilfields and gas fields, which are under active exploitation and reduction of vegetation, dumping technological sites, laying trenches for pipelines, etc. have been noticed, which leads to formation of technogenic soils, damaged land cover, loss of soil fertility and land use type change. There special restoration measure - reclamation should be putted into practice on the territory of all categories of land, but especially on agricultural land. The aim of the article is to study the situation with damaged agricultural land in Samara region of Russia and to develop scientifically based proposals for regeneration of its fertility after reclamation measures. The problems of pollution of agricultural land in the region have been investigated, main sources and types of pollution have been analysed, as well as legal, methodological and environmental protection documents on land reclamation have been studied. The peculiarities of reclamation of land on federal, municipal and property level have been considered. The article presents measures for reclamation of the land on the example of natural monopolies in the territory of the Samara region.

To the experience of Shkapovo oilfield development

The article formulates the main conclusions about the development of a large Shkapovsky oil field with an emphasis on the results of the development of the main objects – horizons DI and DIV of the terrigenous Devonian. The field was commissioned following the neighboring Tuimazinsky and Serafimovsky fields, taking into account the experience of a scientifically organized system for the development of these large platform oil fields in the Volga-Ural oil and gas region. It is shown that this experience was not taken into account much, especially in relation to the unsecured needs of oil production with capital construction, material and technical supply and social facilities. The potential of the field was realized in 18 years. Intra-contour and focal flooding, production technologies using electric centrifugal pumps (ESP), chemicalization of oil extraction processes, primary collection and transportation of products, oil, gas and water treatment technologies, etc., accelerated the development. Shkapov engineers and scientists own a number of innovations: realizing high development rates, means of preventing and eliminating salt-paraffin deposits, the introduction of double-barrel drilling, the development of high-performance ESPs, separate development of facilities, etc. At the same time, tasks were solved on eliminating ecological imbalance in the bowels and the environment, housing and public works. The current urgent problem of the field’s additional development is the activation of the production of residual oil reserves from oil and watered zones drilled with an unreasonably rare grid of wells. The final oil recovery coefficients of the Devonian objects are expected to be high, but, according to the author of the article, could reach CU 0.6.

Igneous petroleum systems in the Malargüe fold and thrust belt, Río Grande Valley area, Neuquén Basin, Argentina

Abstract The Rio Grande Valley (Neuquen Basin, Argentina) is a large oil field where voluminous igneous sill complexes are emplaced in different levels of the sedimentary sequence in a fold and thrust belt setting. These sills are predominantly emplaced in organic-rich units such as Vaca Muerta and Agrio Formations and are critical elements of the defined petroleum system, as they affect the thermal maturity of the surrounding source rocks, and also act as naturally fractured reservoirs. In this contribution, we integrated structural sections, borehole data, core descriptions, petrophysical laboratory tests and organic geochemistry measurements to characterize the impact of the magmatism in the petroleum system of the Rio Grande Valley oil field. Especially, we focused in evaluating the impact of the sill-complexes in hydrocarbon generation, migration and accumulation. Our data shows that: (1) intrusions are preferably emplaced in organic rich units; (2) a large number of intrusions is observed in areas intensely deformed by imbricated thrusts; (3) an increase in the number of intrusions drives stronger and more extensive maturation processes in the Vaca Muerta formation, enhancing notably the cracking of kerogen to hydrocarbon within this unit; (4) where the number of intrusions increases, the concentration of total gas and methane also increases, given that all sills are suitable reservoirs; (5) igneous rocks provide a low resistance path for fluids flow and act as the main reservoirs in the study area; (6) the reservoir quality of igneous intrusions is dominated by the combination of matrix and fracture framework properties; (7) zeolites are the most common type of cement in these reservoirs; (8) deep sills located in the Vaca Muerta formation produce larger volumes of hydrocarbons relative to shallower intrusive reservoirs. The Rio Grande Valley oil field offers a world-class example of the implications of igneous complexes in hydrocarbon generation, migration and accumulation in a compressive tectonic setting of fold and thrust belt.

Studying of speed on the process drill string flattening vertical wells

The issue of vertical wells curvature is important, especially when conducting wells in complex geological conditions of drilling, due to the increasing depth of the wells and the corresponding rise in the cost of drilling. The cause of this circumstance lies in the large time and financial costs while flattening of the bent wells. Moreover, it should be noted that during the subsequent drilling of a curved well the risk of key-seating and the corresponding complications increases. That is why large oil field service companies and drilling enterprises are paying more and more attention to solving the problem of vertical wells curvature. This article is devoted to investigation the effect of rotation of the drill string on the deflecting force on the bit while drilling a vertical well in a rotary way. We suggest using of eccentric drill collars for drilling vertical wells in difficult geological conditions. Also, we create an expression for the dynamic milling force on the bit, taking into account the usage of an eccentric drill collar in the composition of bottom-hole assembly.

Comparison of PAH content, potential risk in vegetation, and bare soil near Daqing oil well and evaluating the effects of soil properties on PAHs.

As the largest oil field in China, Daqing oil field has been developed in the past six decades. The objectives of this study were to measure the levels of polycyclic aromatic hydrocarbons (PAHs) and assess their ecological risk of PAHs in vegetation soil and bare soil near oil well in Daqing and surrounding soil. Ten sites were selected from two types of soil in grassland: vegetation soil (VS, n = 5) and bare soil (BS, n = 5). The mean concentration of 16 PAHs (∑16 PAHs) was 2240.2μg/kg. The mean concentrations of eight carcinogenic PAHs (∑8c PAHs) was 1312.3μg/kg which accounts for 59% of ∑16 PAHs. The sampling sites had higher proportions of high weight molecular ringed PAHs with higher proportions of benzo (a) pyren (BaP) and benzo (k) fluoranthene (BkF). The main source of PAHs was petroleum, coal/biomass combustion, and vehicular emission in these sampling sites. According to Canadian soil quality guidelines, 60% sites had a significant risk to human health. Moreover, 50% sites had high ecological risk and 30% sites were close to this critical value. Notably, PAH levels were significantly higher in VS than BS; moreover, VS had higher organic matter (OM) content, soil dehydrogenase (sDHA) activity, and lower pH and salt content. A structural equation model was established to explore the effects of soil properties on PAH concentration in VS. The result revealed that OM and sDHA were meaningful to enhance the adsorption and biological fixation of PAHs. This study will provide basic information on PAH level and potential application for phytoremediation.

Geofluid dynamic concept of prospecting for hudrocarbon accumulations in the earth crust

In our paper we produce new evidence of the tectonosphere and hydrosphere structure of oil and gas sedimentary basins and confirm significant influence of geofluid-dynamic processes on formation of hydrocarbon accumulations in the crust at the great depths. In our opinion the theory based on obsolete views on the tectonosphere structure lessen the importance the sedimentary migration theory of hydrocarbon generation. We prognosticate a particular stagnant type of post-elysionic water-drive systems in the crust at the great depths in conditions of increased hydrodynamic isolation. Absence of regionally sustained vertical and lateral drainage layers characterizes geological environment where stagnant type developed, and, corollary, fluids outflow into external environment is practically unfeasible. The subsalt filling complexes of the epicontinental deepwater basins are included into the post-elysionic water-drive systems. These complexes occur at the great depths and possibility of striking unique and large oil and gas fields there is inherent. We propose a system of fluid-dynamic conditions for preserving hydrocarbon accumulations in the lower crust as a result of developing sedimentary-migration theory for oil and gas formation. We consider the refinement of methods for prospecting and exploration large deposits at the great depths will pave the way for expanded reproduction of hydrocarbon reserves in the “old” oil and gas producing regions in our country.

Problems of shale oil hydrocarbons, ultra-viscous oil reservoirs and natural bitumen deposits development in Tatarstan

The area of the Volga-Ural oil and gas basin belongs to the “old” oil and gas bearing regions. The most part of easily recoverable reserves of large and unique oil fields already have been developed within the area. Therefore, super-viscous oil reservoirs, natural bitumen deposits and shale hydrocarbons seized the attention of local petroleum geologists. Tatarstan is a classic example in that sense. The Republic of Tatarstan is a leader in the development of heavy oil resources, a leader in the degree of knowledge of natural bitumen accumulations, as well as a leader in technological readiness for their development. In the depths of Tatarstan, there are more than 450 fields of ultra-viscous oil and natural bitumen with reserves ranging from 2 to 7 billion tons of this type of hydrocarbons. However, their industrial development due to low profitability is slow. To solve the problem, it is necessary to search for and commercialize economically viable technologies for the production, transportation and processing of hydrocarbons, which take into account its features and do not require increased energy and other material costs. Therefore, the search for the right unconventional hydrocarbons production concept is an urgent problem of our time.