scholarly journals Production Allocation: Rosetta Stone or Red Herring? Best Practices for Understanding Produced Oils in Resource Plays

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1105
Author(s):  
Craig D. Barrie ◽  
Catherine M. Donohue ◽  
J. Alex Zumberge ◽  
John E. Zumberge
Keyword(s):  
Case Studies ◽  
Time Lapse ◽  
Source Rocks ◽  
Individual Development ◽  
Geochemical Data ◽  
Total Output ◽  
Production Allocation ◽  
The Usa ◽  
Rock Characterization ◽  
End Members

The production of crude oil from resource plays has increased enormously over the past decade. In the USA, around 63% of total output in 2019 was from unconventional production. The major unconventional plays in the USA (e.g., Permian Basin, Anadarko Basin, Eagle Ford, etc.) have become some of the world’s largest oil producers. However, unlike “conventional” exploitation, the target zones in unconventional systems are generally the source rocks themselves or adjacent strata and require numerous horizontal wells and stimulation via hydraulic fracturing to meet production targets. In order to maximize production, operators have developed various well stacking methods, all of which require some form of monitoring to ensure that well spacing is optimized and fluid production is not being “stolen” from adjacent formations, thereby reducing the production potential in associated wells. This necessity, amongst other geochemical considerations related to source rock characterization, has resulted in the expansion of “production allocation” and “time lapse geochemistry” methods. These methods were initially developed for conventional production decades ago, but have since been adapted to unconventional systems. However, the direct applicability of this method is not straightforward and numerous considerations need to be taken into account, foremost among which are: (1) “What defines your end-members?” (2) “Are these end-members valid across a meaningful development area?” and (3) “What is the most appropriate use of geochemistry data in these systems?”. Reservoir geochemistry studies, which include both “time lapse geochemistry/production monitoring” and “production allocation”, are valuable geochemical methods in unconventional plays but need to be used appropriately to provide the cost savings and business direction that operators expect. In this paper, we will discuss a number of case studies, both theoretical and natural, and outline the important factors which need to be considered when designing a reservoir geochemistry study and the common pitfalls which exist. The case studies and best practice approach discussed are designed to highlight the power and flexibility of geochemical data collection methods, integration with the operator’s knowledgebase, and other analytical methods to customize the program for individual development programs. Emphasis is placed upon developing robust and applicable fluid relationships from geochemical data and evidence for statistically significant changes through time.

Identification of uraniferous granitoids in the USA using stream sediment geochemical data

1981 ◽  
Vol 44 (336) ◽  
pp. 455-470 ◽  
Author(s):  
R. J. Howarth ◽  
G. S. Koch ◽  
J. A. Plant ◽  
R. K. Lowry
Keyword(s):  
Trace Element ◽  
Sedimentary Basins ◽  
Stream Sediments ◽  
Uranium Mineralization ◽  
Stream Sediment ◽  
Source Rocks ◽  
Sediment Geochemistry ◽  
Geochemical Data ◽  
Front Range ◽  
The Usa

AbstractTrace element variations in stream sediments from an area of 76 000 km2 in central Colorado are used to identify uraniferous granitoids on the basis of whole rock geochemical criteria developed to distinguish barren from metalliferous granitoids in Britain. These criteria (which include enhanced Ba, Be, Cs, Cs/Ba, K, La/Eu, Li, Lu/Eu, Nb, Rb, Rb/K, low Sr and Mg, and RE patterns with marked negative Eu anomalies) are used to formulate an index based on the Pikes Peak batholith of the Front Range as a type uranium source rock.Uraniferous granitoids in Colorado, which are associated with sedimentary basins containing major uranium mineralization, are identified using this index which may be applicable to the interpretation of stream sediments from elsewhere. The use of stream sediment geochemistry as an exploration method for similar uranium source rocks, which may indicate potential uranium provinces, is thus possible.

ADDRESSING RESERVOIR HETEROGENEITY BY INTEGRATION OF GEOCHEMISTRY AND PETROPHYSICAL LOGS IN CARBONATE PROSPECTS

2021 ◽  
Author(s):  
Kemal C. Hekimoglu ◽  
◽  
Filippo Casali ◽  
Antonio Bonetti ◽  
◽  
...  
Keyword(s):  
Focal Point ◽  
Source Rocks ◽  
Geochemical Data ◽  
Reservoir Properties ◽  
Formation Evaluation ◽  
Geomechanical Properties ◽  
Reservoir Rocks ◽  
Production Allocation ◽  
Petrophysical Logs ◽  
Geochemical Analyses

Formation evaluation challenges in highly fractured, stacked reservoirs with multiple source rocks and structural complexities that have complicated charging histories are common in the Middle East. Finding additional pay zones, understanding the contribution of individual oils to the overall production, or evaluating the compartmentalization within the reservoir by resolving the heterogeneity of the reservoir rocks are to name but a few. This work tries to understand the challenges posed by the subsurface complexities and attempts to find answers through physical evidence, using both onsite data acquired during drilling and data gathered through organic and inorganic laboratory measurements. Formation evaluation challenges are mostly attributed to formation heterogeneity, which we have aimed to address through the integration of petrophysical and geochemical data within this work. This project encompasses the integration of petrophysical and geochemical analyses of the reservoir rocks. Geochemical data have provided the ability to make maturity, richness, and other character interpretations and will be combined with important petrophysical properties of the carbonate intervals to predict reservoir heterogeneities. These interpretations could support perforation interval selection on subsequent wells in the field through the understanding of the mobility of the oils and, ultimately, production allocation. Best practices for thermally extracting hydrocarbons from drill cuttings, quality-controlling advanced mud gas data, and interpretive processes together with the entire workflow followed will also be elaborated. The analysis has the objectives of establishing results to support completion decisions through understanding reservoir quality, reservoir fluid communication, and compartmentalization specific to the basin studied. The petrophysical reservoir properties such as hydrocarbons in place, mobility of the oils, porosity, permeability, fracture intensity, geomechanical properties (brittle vs. ductile), and production allocation will be tied in to geochemical analyses to this extent. The focal point of the work is ascertaining and characterizing both the reservoir properties using a number of integrated analytical techniques on DST oil samples of 12 offset wells and rock cuttings, as well as petrophysical logs and advanced mud gas data. The concepts, tools, and methods that have been demonstrated for evaluating crude oils, natural gases, and petrophysical characteristics of the rocks are applicable to many problems in petroleum production and field development as well as exploration efforts.

scholarly journals Source rock characterization and oil grouping in the NW Java, Central Java and NE Java Basins, Indonesia

2021 ◽  
Vol 47 (2) ◽  
pp. 48-66
Author(s):  
Ragil Pratiwi
Keyword(s):  
Organic Geochemistry ◽  
Hierarchical Cluster ◽  
Source Rocks ◽  
Geochemical Data ◽  
Crude Oils ◽  
Central Java ◽  
Agglomerative Hierarchical Cluster Analysis ◽  
Marine Source ◽  
Group 5 ◽  
Rock Characterization

This study reveals the detailed organic geochemistry from crude oils (acquired from wells and seepages) and rock extracts from NW Java and NE Java Basin that have been gathered and compiled from previous publications. The interpretation was conducted from geochemical data value and plot, GC-MS fingerprints, and agglomerative-hierarchical cluster analysis using the Euclidean algorithm. Various source rocks from those basins were deposited under fluvio-lacustrine to the marine environment. Six groups of crude oils are also distinguished. Groups 1, 2, and 6 are oils from deltaic source rocks, Groups 3 and 4 are oils from marine source rocks, and Group 5 is from lacustrine and/or fluvio-lacustrine source rocks. Groups 1, 2, and 6 could be distinguished from the pristane/phytane (Pr/Ph) ratio and C29 sterane composition, while Groups 3 and 4 differ from the distribution of C27 sterane. The schematic depositional environment of source rocks is also generated from this study and suggests that Group 5 is deposited during early syn-rift non-marine settings, while the remaining groups are deposited in the deltaic (Group 1,2 and 6) and marine settings (Groups 3 and 4). The main differences between those groups are including the distributions of C27-C28-C29 steranes.

Emergent and Adaptive Spiritualities in the Twentieth Century

2018 ◽  
Author(s):  
Andy Lord
Keyword(s):  
Twentieth Century ◽  
Case Studies ◽  
Church Life ◽  
The Usa ◽  
The Uk

This chapter points to the ‘pluralization of the lifeworld’ involved in globalization as a key context for changing dissenting spiritualities through the twentieth century. These have included a remarkable upsurge in Spirit-movements that fall under categories such as Pentecostal, charismatic, neo-charismatic, ‘renewalist’, and indigenous Churches. Spirit language is not only adaptive to globalized settings, but brings with it eschatological assumptions. New spiritualities emerge to disrupt existing assumptions with prophetic and often critical voices that condemn aspects of the existing culture, state, and church life. This chapter outlines this process of disruption of the mainstream in case studies drawn from the USA, the UK, India, Africa, and Indonesia, where charismaticized Christianity has emerged and grown strongly in often quite resistant broader cultures.

Time-Lapse Seismic for Reservoir Management: Case Studies From Offshore Niger Delta, Nigeria

2016 ◽  
Vol 19 (03) ◽  
pp. 391-402
Author(s):  
Sunday Amoyedo ◽  
Emmanuel Ekut ◽  
Rasaki Salami ◽  
Liliana Goncalves-Ferreira ◽  
Pascal Desegaulx
Keyword(s):  
Case Studies ◽  
Niger Delta ◽  
Reservoir Management ◽  
Time Lapse ◽  
Seismic Survey ◽  
Elastic Model ◽  
Field Development ◽  
4D Seismic ◽  
The Impact

Summary This paper presents case studies focused on the interpretation and integration of seismic reservoir monitoring from several fields in conventional offshore and deepwater Niger Delta. The fields are characterized by different geological settings and development-maturity stages. We show different applications varying from qualitative to quantitative use of time-lapse (4D) seismic information. In the first case study, which is in shallow water, the field has specific reservoir-development challenges, simple geology, and is in phased development. On this field, 4D seismic, which was acquired several years ago, is characterized by poor seismic repeatability. Nevertheless, we show that because of improvements from seismic reprocessing, 4D seismic makes qualitative contributions to the ongoing field development. In the second case study, the field is characterized by complex geological settings. The 4D seismic is affected by overburden with strong lateral variations in velocity and steeply dipping structure (up to 40°). Prestack-depth-imaging (PSDM) 4D seismic is used in a more-qualitative manner to monitor gas injection, validate the geologic/reservoir models, optimize infill injector placement, and consequently, enhance field-development economics. The third case study presents a deep offshore field characterized by a complex depositional system for some reservoirs. In this example, good 4D-seismic repeatability (sum of source- and receiver-placement differences between surveys, dS+dR) is achieved, leading to an increased quantitative use of 4D monitoring for the assessment of sand/sand communication, mapping of oil/water (OWC) front, pressure evolution, and dynamic calibration of petro-elastic model (PEM), and also as a seismic-based production-logging tool. In addition, 4D seismic is used to update seismic interpretation, provide a better understanding of internal architecture of the reservoirs units, and, thereby, yield a more-robust reservoir model. The 4D seismic in this field is a key tool for field-development optimization and reservoir management. The last case study illustrates the need for seismic-feasibility studies to detect 4D responses related to production. In addition to assessing the impact of the field environment on the 4D- seismic signal, these studies also help in choosing the optimum seismic-survey type, design, and acquisition parameters. These studies would possibly lead to the adoption of new technologies such as broad-band streamer or nodes acquisition in the near future.

scholarly journals Source rock characterization of mesozoic to cenozoic organic matter rich marls and shales of the Eratosthenes Seamount, Eastern Mediterranean Sea

2018 ◽  
Vol 73 ◽  
pp. 49 ◽  
Author(s):  
Sebastian Grohmann ◽  
Susanne W. Fietz ◽  
Ralf Littke ◽  
Samer Bou Daher ◽  
Maria Fernanda Romero-Sarmiento ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mediterranean Sea ◽  
Source Rock ◽  
Eastern Mediterranean ◽  
Source Rocks ◽  
Eastern Mediterranean Sea ◽  
Potential Source Rock ◽  
Levant Basin ◽  
Rock Characterization ◽  
Rock Eval

Several significant hydrocarbon accumulations were discovered over the past decade in the Levant Basin, Eastern Mediterranean Sea. Onshore studies have investigated potential source rock intervals to the east and south of the Levant Basin, whereas its offshore western margin is still relatively underexplored. Only a few cores were recovered from four boreholes offshore southern Cyprus by the Ocean Drilling Program (ODP) during the drilling campaign Leg 160 in 1995. These wells transect the Eratosthenes Seamount, a drowned bathymetric high, and recovered a thick sequence of both pre- and post-Messinian sedimentary rocks, containing mainly marine marls and shales. In this study, 122 core samples of Late Cretaceous to Messinian age were analyzed in order to identify organic-matter-rich intervals and to determine their depositional environment as well as their source rock potential and thermal maturity. Both Total Organic and Inorganic Carbon (TOC, TIC) analyses as well as Rock-Eval pyrolysis were firstly performed for the complete set of samples whereas Total Sulfur (TS) analysis was only carried out on samples containing significant amount of organic matter (>0.3 wt.% TOC). Based on the Rock-Eval results, eight samples were selected for organic petrographic investigations and twelve samples for analysis of major aliphatic hydrocarbon compounds. The organic content is highly variable in the analyzed samples (0–9.3 wt.%). TS/TOC as well as several biomarker ratios (e.g. Pr/Ph < 2) indicate a deposition under dysoxic conditions for the organic matter-rich sections, which were probably reached during sporadically active upwelling periods. Results prove potential oil prone Type II kerogen source rock intervals of fair to very good quality being present in Turonian to Coniacian (average: TOC = 0.93 wt.%, HI = 319 mg HC/g TOC) and in Bartonian to Priabonian (average: TOC = 4.8 wt.%, HI = 469 mg HC/g TOC) intervals. A precise determination of the actual source rock thickness is prevented by low core recovery rates for the respective intervals. All analyzed samples are immature to early mature. However, the presence of deeper buried, thermally mature source rocks and hydrocarbon migration is indicated by the observation of solid bitumen impregnation in one Upper Cretaceous and in one Lower Eocene sample.

The Cottage: providing medical respite care in a home-like environment for people experiencing homelessness

2018 ◽  
Vol 22 (1) ◽  
pp. 54-64
Author(s):  
Angela Gazey ◽  
Shannen Vallesi ◽  
Karen Martin ◽  
Craig Cumming ◽  
Lisa Wood
Keyword(s):  
Case Studies ◽  
Small Sample Size ◽  
Treatment Compliance ◽  
Small Sample ◽  
Health Conditions ◽  
Hospital Inpatient ◽  
City Hospital ◽  
Post Discharge ◽  
Content Type ◽  
The Usa

Purpose Co-existing health conditions and frequent hospital usage are pervasive in homeless populations. Without a home to be discharged to, appropriate discharge care and treatment compliance are difficult. The Medical Respite Centre (MRC) model has gained traction in the USA, but other international examples are scant. The purpose of this paper is to address this void, presenting findings from an evaluation of The Cottage, a small short-stay respite facility for people experiencing homelessness attached to an inner-city hospital in Melbourne, Australia. Design/methodology/approach This mixed methods study uses case studies, qualitative interview data and hospital administrative data for clients admitted to The Cottage in 2015. Hospital inpatient admissions and emergency department presentations were compared for the 12-month period pre- and post-The Cottage. Findings Clients had multiple health conditions, often compounded by social isolation and homelessness or precarious housing. Qualitative data and case studies illustrate how The Cottage couples medical care and support in a home-like environment. The average stay was 8.8 days. There was a 7 per cent reduction in the number of unplanned inpatient days in the 12-months post support. Research limitations/implications The paper has some limitations including small sample size, data from one hospital only and lack of information on other services accessed by clients (e.g. housing support) limit attribution of causality. Social implications MRCs provide a safe environment for individuals to recuperate at a much lower cost than inpatient admissions. Originality/value There is limited evidence on the MRC model of care outside of the USA, and the findings demonstrate the benefits of even shorter-term respite post-discharge for people who are homeless.

Petrologic and thermal constraints on the origin of leucogranites in collisional orogens

2004 ◽  
Vol 95 (1-2) ◽  
pp. 73-85 ◽  
Author(s):  
Peter I. Nabelek ◽  
Mian Liu
Keyword(s):  
Partial Melting ◽  
Shear Zones ◽  
Source Rocks ◽  
Radioactive Isotopes ◽  
The Usa ◽  
Appalachian Orogen ◽  
Shear Heating ◽  
Heating Model ◽  
Orogenic Belts ◽  
Collisional Orogens

ABSTRACTLeucogranites are typical products of collisional orogenies. They are found in orogenic terranes of different ages, including the Proterozoic Trans-Hudson orogen, as exemplified in the Black Hills, South Dakota, and the Appalachian orogen in Maine, both in the USA, and the ongoing Himalayan orogen. Characteristics of these collisional leucogranites show that they were derived from predominantly pelitic sources at the veining stages of deformation and metamorphism in upper plates of thickened crusts. Once generated, the leucogranite magmas ascended as dykes and were emplaced within shallower parts of their source sequences. In these orogenic belts, there was a strong connection between deformation, metamorphism and granite generation. However, the heat sources needed for partial melting of the source rocks remain controversial. Lack of evidence for significant intrusion of mafic magmas necessary to cause melting of upper plate source rocks suggests that leucogranite generation in collisional orogens is mainly a crustal process.The present authors evaluate five types of thermal models which have previously been proposed for generating leucogranites in collisional orogens. The first, a thickened crust with exponentially decaying distribution of heat-producing radioactive isotopes with depth, has been shown to be insufficient for heating the upper crust to melting conditions. Four other models capable of raising the crustal temperatures sufficiently to initiate partial melting of metapelites in thickened crust include: (1) thick sequences of sedimentary rocks with high amounts of internal radioactive heat production; (2) decompression melting; (3) thinning of mantle lithosphere; and (4) shear-heating. The authors show that, for reasonable boundary conditions, shear-heating along crustal-scale shear zones is the most viable process to induce melting in upper plates of collisional orogens where pelitic source lithologies are usually located. The shear-heating model directly links partial melting to the deformation and metamorphism that typically precede leucogranite genera

Exemples de mélange de magmas en contexte plutonique: les enclaves des tonalites–granodiorites du massif de Bono (Sardaigne septentrionale)

1989 ◽  
Vol 26 (6) ◽  
pp. 1264-1281 ◽  
Author(s):  
C. Cocirta ◽  
J. B. Orsini ◽  
C. Coulon
Keyword(s):  
Geochemical Data ◽  
Mixing Process ◽  
Calc Alkaline ◽  
Specific Group ◽  
Mineralogical Analysis ◽  
Magmatic Origin ◽  
Interaction Mechanisms ◽  
Compositional Variations ◽  
End Members ◽  
Host Rocks

In calc-alkaline orogenic plutons, the dark xenoliths and their host rocks must be considered the expression of partial mixing of magma.Three associations of this type have been investigated and are illustrated by the Bono pluton (northern Sardinia)— a composite pluton including three intrusives of different nature (tonalitic to granodioritic) and containing a very large number of basaltic xenoliths of magmatic origin. Detailed mineralogical analysis of the two end members in each association, coupled with geochemical data, has determined the major petrogenetic mechanisms intervening in the mixing process in a plutonic setting: temperature equilibration, mechanical exchanges of crystals, chemical exchanges, etc. The most important result of this article, however, is to show that each intrusion is related to a specific group of xenoliths that is characterized by constant FeOt/MgO. The latter reflects the different composition of basaltic components, and it is concluded that each intrusive event is associated with a unique mixing episode. As in volcanic settings, the mixing process may have initiated the intrusion.The extreme compositional variations in the magmatic xenoliths, recognized in several series of orogenic plutons, is explained here by different initial basaltic end members and by variation in the intensity of the interaction mechanisms. [Journal Translation]

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