Advances in Elemental Spectroscopy Logging: A Cased Hole Application Offshore West Africa

Rising costs for exploration and developments and more stringent need to secure any additional drop of oil have put operators’ margins under increasing pressure. Coupled with the recent oil price decline, this call for efficiency and diligence to be the main drivers for any formation evaluation and planning for development and production. The reservoirs in Western offshore Africa are so diverse in the settings that two reservoirs hardly show any correlation. The complexity associated with the Rifting of African plate from South American plate has introduced significant geological challenges, adding to even bigger challenges in Petrophysical analysis. The mineralogy is complex; clay characterization is often unsolved. The formation waters are fresh with variable salinity and there is occurrence of thin shale laminations and grain size variations contributing to low resistivity low contrast pay generation. Advanced and fit-to-purpose logging technologies and computational methods are needed for rock quality and potential. Moreover, in some cases the accessibility of the target reservoir is difficult and risky, so that formation evaluation must be performed behind casing.The high definition spectroscopy tool is the latest development in wireline spectroscopy measurements. Its technological advances revolutionize the neutron-induced gamma ray methodology to support robust lithology and saturation interpretation in formations with complex mineralogy and fluid content. The ability to determine both the matrix mineral composition and total organic carbon (TOC) are instrumental to the geoscientist, the petrophysicist, the reservoir engineer, and the completion engineer. In the region, the use of high definition spectroscopy measurement has been pioneered while pursuing better understanding of rock composition and more accurate reservoir models in complex lithology and fresh formation waters with low resistivity contrast. The results are beneficial at the various stages of a field development and provide critical input to the petrophysical reserves estimate.In the example described in this paper, the new technology has proven to be critical to evaluate a complex reservoir system independent of the water salinity and resistivity offshore Gulf of Guinea, even with logging behind casing. A comprehensive set of quality outputs is made available for accurate reservoir quality; the logs data processing is performed within the critical-hours after logging to enable informed decision making.

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A Novel Workflow for Geosteering a Horizontal Well in a Low Resistivity Contrast Anisotropic Environment: A Case Study in Semoga Field, Indonesia

10.2118/204547-ms ◽

2021 ◽

Author(s):

Yessica Fransisca ◽

Karinka Adiandra ◽

Vinda Manurung ◽

Laila Warkhaida ◽

M. Aidil Arham ◽

...

Keyword(s):

Real Time ◽

Horizontal Well ◽

Gamma Ray ◽

Lessons Learned ◽

Electrical Anisotropy ◽

Anisotropy Ratio ◽

Well Placement ◽

Low Contrast ◽

Low Resistivity ◽

The Subject

Abstract This paper describes the combination of strategies deployed to optimize horizontal well placement in a 40 ft thick isotropic sand with very low resistivity contrast compared to an underlying anisotropic shale in Semoga field. These strategies were developed due to previously unsuccessful attempts to drill a horizontal well with multiple side-tracks that was finally drilled and completed as a high-inclined well. To maximize reservoir contact of the subject horizontal well, a new methodology on well placement was developed by applying lessons learned, taking into account the additional challenges within this well. The first approach was to conduct a thorough analysis on the previous inclined well to evaluate each formation layer’s anisotropy ratio to be used in an effective geosteering model that could better simulate the real time environment. Correct selections of geosteering tools based on comprehensive pre-well modelling was considered to ensure on-target landing section to facilitate an effective lateral section. A comprehensive geosteering pre-well model was constructed to guide real-time operations. In the subject horizontal well, landing strategy was analysed in four stages of anisotropy ratio. The lateral section strategy focused on how to cater for the expected fault and maintain the trajectory to maximize reservoir exposure. Execution of the geosteering operations resulted in 100% reservoir contact. By monitoring the behaviour of shale anisotropy ratio from resistivity measurements and gamma ray at-bit data while drilling, the subject well was precisely landed at 11.5 ft TVD below the top of target sand. In the lateral section, wellbore trajectory intersected two faults exhibiting greater associated throw compared to the seismic estimate. Resistivity geo-signal and azimuthal resistivity responses were used to maintain the wellbore attitude inside the target reservoir. In this case history well with a low resistivity contrast environment, this methodology successfully enabled efficient operations to land the well precisely at the target with minimum borehole tortuosity. This was achieved by reducing geological uncertainty due to anomalous resistivity data responding to shale electrical anisotropy. Recognition of these electromagnetic resistivity values also played an important role in identifying the overlain anisotropic shale layer, hence avoiding reservoir exit. This workflow also helped in benchmarking future horizontal well placement operations in Semoga Field. Technical Categories: Geosteering and Well Placement, Reservoir Engineering, Low resistivity Low Contrast Reservoir Evaluation, Real-Time Operations, Case Studies

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Reduced Well Construction Time with Accurate Geostopping in Harsh Drilling Conditions: Case Study from Kuwait

10.2118/202077-ms ◽

2021 ◽

Author(s):

Khaled Saleh ◽

Abdulaziz Bader Al-Khudari ◽

Amer Al-Najdi ◽

Mejbel Saad Al-Azmi ◽

Fahad Barrak Al-Otaibi ◽

...

Keyword(s):

Gamma Ray ◽

Wellbore Stability ◽

Construction Time ◽

Evaluation Data ◽

Pressure Drops ◽

Formation Evaluation ◽

Field Development ◽

Pull Out ◽

Solids Content ◽

A Minor

Abstract Traditionally, 12.25-in. hole sections in the Jurassic formations were planned to be drilled with mud weight (MW) of 20 ppg and solids content of 45%. The planned drilling would use a rotary assembly from the Hith formation, crossing several zones in which mud losses or gains were likely. The casing would then be set in the thin shale base of the Gotnia formation. A minor inaccuracy in casing setting depth could often lead to well-control issues. Pore pressure drops severely below the shale base and requires a MW of 15 ppg. Passing this shale base can lead to severe losses and potential abandonment of the well. An anhydrite marker is located approximately 50 ft above the shale base. To reduce risk, the operator would normally drill to this marker at a rate of penetration (ROP) of 20-30 ft/hr, then decrease the ROP to 2 ft/hr. While slowly drilling the last part of the section, penetration would be stopped every few feet to circulate bottoms-up to receive samples confirming the shale base; this process requires an additional 24 hours of rig time. After reaching the casing point, the operator would pull out of the hole to pick up logging-while-drilling (LWD) tools to perform a wiping run. This logging, however, is frequently cancelled because of wellbore stability issues, resulting in the loss of important formation-evaluation data across this interval. A new solution has been developed, comprising drilling with a rotary assembly to the final anhydrite marker, then pulling the string out of hole to pick up LWD triple-combo and sonic tools, with a conventional gamma ray sensor placed only 6 ft from the bit. The remaining part of the section would then be drilled at 7-10 ft/hr until the gamma-ray tool detected the shale base, thereby determining the casing depth. In addition, it was planned to re-log the previously drilled interval. This solution prevented the well from potential abandonment and reduced drilling time. It also secured critical formation evaluation data for exploration and future field development. The engineered drilling solution was tried for the first time in these formation sequences within a harsh drilling and logging environment. The option of rotary steerable services with an at-bit GR sensor was not considered because of the high cost.

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Novel application of three-dimensional HDlive imaging in prenatal diagnosis from the first trimester

Journal of Perinatal Medicine ◽

10.1515/jpm-2014-0157 ◽

2015 ◽

Vol 43 (2) ◽

Cited By ~ 5

Author(s):

Ritsuko Kimata Pooh ◽

Asim Kurjak

Keyword(s):

Human Development ◽

New Technology ◽

Three Dimensional ◽

First Trimester ◽

High Definition ◽

Noninvasive Diagnostics ◽

Anatomy And Physiology ◽

Early Human Development ◽

2D Ultrasound ◽

Early Human

AbstractRecent development of three-dimensional (3D) high definition (HD) ultrasound has resulted in remarkable progress in visualization of early embryos and fetuses in sonoembryology. The new technology of HDlive assesses both structural and functional developments in the first trimester with greater reliably than two-dimensional (2D) ultrasound. The ability to visualize not only fetal face, hands, fingers, feet, and toes, but also amniotic membranes, is better with volumetric ultrasound than 2D ultrasound. In this article, detailed and comprehensive structures of normal and abnormal fetuses depicted by 3D HDlive are presented, including various faces of Down’s syndrome and holoprosencephaly, as well as low-set ear and finger/toe abnormalities from the first trimester. Three-dimensional HDlive further “humanizes” the fetus, enables detailed observation of the fetal face in the first trimester as shown in this article, and reveals that a small fetus is not more a fetus but a “person” from the first trimester. There has been an immense acceleration in understanding of early human development. The anatomy and physiology of embryonic development is a field where medicine exerts greatest impact on early pregnancy at present, and it opens fascinating aspects of embryonic differentiation. Clinical assessment of those stages of growth relies heavily on 3D/four-dimensional (4D) HDlive, one of the most promising forms of noninvasive diagnostics and embryological phenomena, once matters for textbooks are now routinely recorded with outstanding clarity. New advances deserve the adjective “breathtaking”, including 4D parallel study of the structural and functional early human development.

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The American Record in Industrial Policy: Results of Programs for Troubled Manufacturing Industries

Journal of Policy History ◽

10.1017/s0898030600003924 ◽

1994 ◽

Vol 6 (3) ◽

pp. 185-214

Author(s):

Margaret E. Dewar

Keyword(s):

Information Technology ◽

New Technology ◽

Manufacturing Industries ◽

Foreign Competition ◽

High Definition ◽

Trade Restrictions ◽

Technological Revolution ◽

High Definition Television ◽

Declining Industries ◽

Manufacturing Sectors

As many manufacturing industries have declined and as much American manufacturing has become vulnerable to foreign competition, numerous groups have suggested that programs to intervene in specific manufacturing sectors could help. Proponents focus on aid to telecommunications, aerospace, information technology, and high-definition television, where an edge in new technology may be key to the industries' success, but they also touch on aid to declining industries. Opponents of trade restrictions often argue that policies should facilitate adjustment in industries injured by trade. Other groups call for a technological “revolution” in manufacturing to restore international competitiveness through programs to facilitate adjustment and to speed the transition to new kinds of manufacturing. Others, concerned about massive job losses in depressed manufacturing communities, have called for improving the welfare of workers and communities.

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Low Resistivity Pay Carbonates: A Practical Approach to Quantify Water Saturation Using a Modified Archie's Model

10.2118/206096-ms ◽

2021 ◽

Author(s):

Ramsin Eyvazzadeh ◽

Abdullatif Al-Omair ◽

Majed Kanfar ◽

Achong Christon

Keyword(s):

Machine Learning ◽

Water Saturation ◽

Pore Space ◽

Learning Algorithms ◽

Machine Learning Algorithms ◽

Theoretical Research ◽

Low Contrast ◽

Practical Applications ◽

Low Resistivity ◽

New Models

Abstract A detailed description of a modified Archie's equation is proposed to accurately quantify water saturation within low resistivity/low contrast pay carbonates. The majority of previous work on low resistivity/low contrast reservoirs focused on clastics, namely, thin beds and/or clay effects on resistivity measurements. Recent publications have highlighted a "non-Archie" behavior in carbonates with complex pore structures. Several theoretical models were introduced, but new practical applications were not derived to solve this issue. Built upon previous theoretical research in a holistic approach, new models and workflows have been developed. Specifically, utilizing a combination of machine learning algorithms, nuclear magnetic resonance (NMR), core and geological data, field specific calibrated equations to compute water saturation (Sw) in complex carbonate formations are presented. Essentially, these new models partition the porosity into pore spaces and calculate their relative contribution to water saturation in each pore space. These calibrated equations robustly produce results that have proven invaluable in pay identification, well placement, and have greatly enhanced the ability to manage these types of reservoirs. This paper initially explains the theory behind the development of the analysis illustrating workflows and validation techniques used to qualify this methodology. A key benefit performing this research is the utilization of machine-learning algorithms to predict NMR derived values in wells that do not have NMR data. Several examples explore where results of this analysis are compared to dynamic testing, formation testing and laboratory measured samples to validate and demonstrate the utility of this new analysis.

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Significance of The Sedimentology and Stratigraphy for Identification of Low Contras Low Resistivity zones in a Clastic Outcrop of The Upper Talang Akar Formation, Musi Banyuasin, Indonesia

10.29118/ipa21-sg-290 ◽

2021 ◽

Author(s):

A. F. H. Surbakti

Keyword(s):

Clay Minerals ◽

Coarse Grained ◽

The South ◽

Reservoir Properties ◽

Low Contrast ◽

Facies Distribution ◽

Low Resistivity ◽

Different Sources

The Talang Akar Formation is one of the hydrocarbon-producing reservoirs of the South Sumatra Basin. This basin is filled from two different sources in the Eastern part and Western part paleo-high. The bottom Talang Akar consists of coarse-grained sandstone, and the upper part constrains intercalation of sandstone and shale, known as low resistivity low contrast zone (LRLC). The Talang Akar Formation from Air Batu and Sukomoro confers an excellent probability to observe and define LRLC zones over systematic approaches. This paper will provide an analogue of the LRLC reservoir zone by analyzing the relation between facies distribution and reservoir properties, including detailed shale structure. Facies distribution was obtained from the outcrop stratigraphic profile. The reservoir properties are identified by the Thomas Stieber plot and the petrographic section. Seven facies of Talang Akar Formation had been identified, which are: 1) planar cross-bedded sandstone (PCBS), 2) trough cross-bedded sandstone (TCBSS), 3) laminated sandstone (LSS), 4) heterolytic sandstone (HSS), 5) clay-rich sandstone (CSS), 6) mudstone (MS), 7) scour conglomeratic sandstone (SCSS). There are several types of shale distribution: structural shale, dispersed shale, and laminar shale. The laminar and dispersed shale consists of most of the reservoir and fills the pore. The clay structure deduces the disparity in the facies-porosity correlation. The finding of this study revealed that the LRLC zones are caused by lamination structures, thin intercalation layers, heterolytic and clay minerals.

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Identification and characterization of low resistivity low contrast zones in a clastic outcrop from Sarawak, Malaysia

Journal of Applied Geophysics ◽

10.1016/j.jappgeo.2018.11.013 ◽

2019 ◽

Vol 160 ◽

pp. 207-217 ◽

Cited By ~ 1

Author(s):

Muhammad Atif Iqbal ◽

Ahmed Mohamed Ahmed Salim ◽

Hassan Baioumy ◽

Gamal Ragab Gaafar ◽

Ali Wahid

Keyword(s):

Low Contrast ◽

Low Resistivity ◽

Identification And Characterization

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High-energy astrophysics and the search for sources of gravitational waves

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2017.0294 ◽

2018 ◽

Vol 376 (2120) ◽

pp. 20170294 ◽

Cited By ~ 1

Author(s):

P. T. O'Brien ◽

P. Evans

Keyword(s):

Gravitational Wave ◽

Short Duration ◽

Gamma Ray ◽

New Technology ◽

High Energy ◽

Compact Objects ◽

Wide Field ◽

High Energy Radiation ◽

Energy Radiation ◽

Binary Mergers

The dawn of the gravitational-wave (GW) era has sparked a greatly renewed interest into possible links between sources of high-energy radiation and GWs. The most luminous high-energy sources—gamma-ray bursts (GRBs)—have long been considered as very likely sources of GWs, particularly from short-duration GRBs, which are thought to originate from the merger of two compact objects such as binary neutron stars and a neutron star–black hole binary. In this paper, we discuss: (i) the high-energy emission from short-duration GRBs; (ii) what other sources of high-energy radiation may be observed from binary mergers; and (iii) how searches for high-energy electromagnetic counterparts to GW events are performed with current space facilities. While current high-energy facilities, such as Swift and Fermi, play a crucial role in the search for electromagnetic counterparts, new space missions will greatly enhance our capabilities for joint observations. We discuss why such facilities, which incorporate new technology that enables very wide-field X-ray imaging, are required if we are to truly exploit the multi-messenger era. This article is part of a discussion meeting issue ‘The promises of gravitational-wave astronomy’.

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Determination of radiosensitivity of Coffea arabica var. 'Venecia' seeds to gamma-ray irradiation.

10.1079/9781789249095.0033 ◽

2021 ◽

pp. 320-325

Author(s):

Reina Céspedes ◽

Noel Arrieta ◽

Miguel Barquero ◽

Ana Abdelnour ◽

Nielen Stephan ◽

...

Keyword(s):

Seed Germination ◽

Coffea Arabica ◽

Gamma Ray ◽

Raw Materials ◽

New Technology ◽

Mutation Breeding ◽

Mutation Induction ◽

Rust Disease ◽

Sources Of Resistance ◽

Breeding Programmes

Abstract Coffee is one of the most commercially available raw materials, being the tropical product with the highest market value in the world. In Costa Rica it is the third most important product for agricultural exports and provides the main income for many families in the country. However, coffee is under threat due to coffee leaf rust disease (CLR). Mutation breeding in coffee is a promising approach to develop new varieties resistant to CLR. As a new technology for coffee, basic tests related to mutation induction need to be done. The plant material used was Coffea arabica var. 'Venecia' seeds, with a moisture content of 27.3%. The applied irradiation doses were 0, 80, 100, 120, 140, 160 and 180 Gy. For each treatment, three replicates of 200 g were used, with a seed number range of 765-808 units per replicate. The irradiated seeds were planted on the same day. Eighty days after treatment the number of seedlings was quantified, the hypocotyl height and radicle length were measured and the opening of cotyledons was determined for each dose. The effects of the radiation doses on seed germination frequency were recorded. At the dose of 80 Gy, germination was reduced over the control by 9.65%, at 100 Gy by 34.06%, at 120 Gy by 52.76%, at 140 Gy by 60.24%, at 160 Gy by 65.56% and at 180 Gy by 75.40%. Seedling growth was affected and a delay in opening of the cotyledons was observed at higher doses. This radiosensitivity test, based on seed germination as compared with unirradiated control, revealed that the LD50 for the variety tested is in the range 100-120 Gy experimentally, and according to the regression is 125 ± 30 Gy. This dose will be used for further bulk experiments and is of great importance, because the LD50 is considered as the range where the appearance of useful mutations in breeding programmes is favoured. The establishment of these parameters is a necessary advance to continue with measurements of genetic and phenotypical parameters to implement mutation breeding in coffee looking for new sources of resistance against CLR.

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