A method for two-well correlation using multivariate biostratigraphical data

2005 ◽  
pp. 205-217 ◽  
Author(s):  
A.C. Gary ◽  
G.W. Johnson ◽  
D.D. Ekart ◽  
E. Platon ◽  
M.I. Wakefield
Keyword(s):  
Well Correlation

A new method for monitoring the redox potential of fuel salt based on the deposition of 95Nb on Hastelloy C276

2021 ◽  
Vol 109 (5) ◽  
pp. 357-365
Author(s):  
Zhiqiang Cheng ◽  
Zhongqi Zhao ◽  
Junxia Geng ◽  
Xiaohe Wang ◽  
Jifeng Hu ◽  
...  
Keyword(s):  
Redox Potential ◽  
Molten Salt ◽  
Specific Activity ◽  
Chemical Reduction ◽  
Quantitative Approach ◽  
Experimental Results ◽  
New Method ◽  
Molten Salt Reactor ◽  
Fuel Salt ◽  
Well Correlation

Abstract To develop the application of 95Nb as an indicator of redox potential for fuel salt in molten salt reactor (MSR), the specific activity of 95Nb in FLiBe salt and its deposition of 95Nb on Hastelloy C276 have been studied. Experimental results indicated that the amount of 95Nb deposited on Hastelloy C276 resulted from its chemical reduction exhibited a positive correlation with the decrease of 95Nb activity in FLiBe salt and the relative deposition coefficient of 95Nb to 103Ru appeared a well correlation with 95Nb activity in FLiBe salt. Both correlations implied that the measurement of 95Nb activity deposited on Hastelloy C276 specimen might provide a quantitative approach for monitoring the redox potential of fuel salt in MSR.

scholarly journals Diurnal variation effect in marine magnetometric surveys: clues from surveys in southeast Brazil

2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Paula Possamai Sergipe ◽  
Yára Regina Marangoni ◽  
Roberto Paulo Zanon dos Santos ◽  
Denise Silva de Moura ◽  
Luigi Jovane
Keyword(s):  
Magnetic Field ◽  
Continental Shelf ◽  
Diurnal Variation ◽  
Brazilian Coast ◽  
Observatory Data ◽  
Before And After ◽  
Corrected Data ◽  
Well Correlation ◽  
The Magnetic Field ◽  
Magnetic Observatories

AbstractThe diurnal variation of the magnetic field cannot be predicted or modeled and for that reason, it is monitored during the magnetic surveys, usually by a stationary magnetometer. However, marine surveys have a practical issue with diurnal monitoring, owing to the distance between the survey, stationary magnetometers, and magnetic observatories. This work aims to verify the use of nearby magnetic observatories to estimate the diurnal variation correction in different marine surveys and evaluate its effectiveness. In this study, we selected surveys at the continental shelf near Santos city (Survey 1), continental slope next to the first survey location (Survey 2), continental shelf near Ubatuba city (Survey 3), and Mamanguá ria in the Paraty city (Survey 4), all southeast to the Brazilian coast. The crossing points were implemented to compare the magnetic field values at different times and days at the same measurement point, before and after the correction. Afterwards, we measure the Pearson’s Correlation of the raw data and the diurnal corrected data in all crossing points of each survey which showed an improvement after correction by the value approximating to 1, which indicates a very well correlation. The Ubatuba and Mamanguá surveys allowed comparing the observatory correction results with the base magnetometer results that were rather similar. Our analyses indicate a satisfactory diurnal correction using the observatory data and the crossing points approach, which can be used for every marine magnetometric survey worldwide placed near the coast (< 280 km) that do not have a stationary magnetometer available.

Hybrid pattern matching algorithms for automated stratigraphic well correlation and log pattern recognition in Malaysian Basin

2021 ◽  
Author(s):  
A.S. Abdrahman ◽  
M.S. Jaya ◽  
A.R. Ali ◽  
A.H. Hasan ◽  
A.R. Ghazali ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Pattern Matching ◽  
Well Correlation

Characteristic of Tuwayil Formation and New Insight into its Contribution in Middle Cretaceous Petroleum System, Western UAE

2021 ◽  
Author(s):  
Dengyi Xiao ◽  
Mingsheng Lv ◽  
Guangcheng Hu ◽  
Wenyuan Tian ◽  
Li Wang ◽  
...  
Keyword(s):  
Sedimentary Facies ◽  
Petroleum System ◽  
Adjacent Area ◽  
Accumulation Mechanism ◽  
Single Well ◽  
Seal Oil ◽  
Well Correlation ◽  
Well Data ◽  
Intrashelf Basin ◽  
Exploration Activity

Abstract In Western UAE, the Middle Cretaceous petroleum system is composed of Shilaif source, Mishrif/Tuwayil reservoir and Tuwayil/Ruwaydha seal. Oil is discovered in Tuwayil sandstone in DH and NN fields. Well correlation of Tuwayil siliciclastic interval shows high heterogeneity and rapid lithology varies. Currently, a few general studies about Tuwayil sandstone was published. However, detailed sedimentary facies, reservoir characteristics and accumulation mechanism about Tuwayil are ambiguous. Limitation on these aspects prohibits enlarging exploration activity of Tuwayil and makes barriers to deepen understanding of the whole K2 PS. To enhance understanding on Tuwayil formation, well data in DH, NN fields and adjacent area was integrated. Dedicated single well analysis, well correlation and petrophysics study were carried out. Cores were observed and laboratory outcomes including TS, SEM, RCA, MICP, XRD were adopted into this study. Furthermore, we have also utilized 2D&3D seismic to illustrate the spatial distribution of Tuwayil siliciclastic setting and interior sediment pattern. Basically, the Tuwayil sand-shale interval represents the infilling of Mishrif/Shilaif intrashelf basin and mainly deposits in the tidal flat-delta facies. The epi-continental clast is sourced from the Arabian shield and transferred from west to east. In Western UAE, the Tuwayil depocenter located in DH field, where 4-5 sand layers deposit with net pay of 30-40ft. In NN field, only one sand layer develops with net pay about 4-6ft. Through deposition cycles identification and seismic reflection observation, two sand groups could be recognized in this interval. The lower group is constrained in the depocenter and influenced by the paleo-geomorphology background. The upper group overpassed the former set and pinched out around north of NN. The Mishrif/Shilaif slope area is another potential belt to enlarge Tuwayil discovery, where stratigraphic onlap could be observed and it probably represents the sand pinch-out in lower sand group. For the K2 PS, previous study believed the shale between Tuwayil sand and Mishrif separate these two reservoirs and works as cap rock for Mishrif grainstone. This study suggests that this shale is too thin and not continuous enough to hold the hydrocarbon in Mishrif. On that note, Tuwayil sand and Mishrif belong to the same petroleum system in NN and may have the same OWC. In the NN field, it is quite crucial to consider the extension of Tuwayil sand during evaluating the stratigraphic prospect of Mishrif because the hydrocarbon is mostly likely charged Tuwayil sand first and then gets into underlain Mishrif. This study provides updates and understandings on sedimentary facies, depositional pattern, hydrocarbon accumulation mechanism, reservoir extension and potential identification of Tuwayil formation, which has inspiring implications for the whole K2 PS and could also de-risk the further exploration activity in Western UAE.

Advanced Horizontal Well Correlation Method for Dynamic Update of Subsurface Layers While Geosteering

2021 ◽  
Author(s):  
Abdul Mohsen Al-Maskeen ◽  
Sadaqat Ali
Keyword(s):  
Real Time ◽  
Horizontal Well ◽  
Control Point ◽  
Correlation Method ◽  
Thickness Variation ◽  
Structural Framework ◽  
Framework Model ◽  
Subsurface Layers ◽  
The Creation ◽  
Well Correlation

Abstract A new automated approach to well correlation is presented that utilizes real-time Logging While-Drilling (LWD) data and predicted well curve to dynamically update subsurface layers during geosteering operations. The automatically created predicted log and a dynamically updated structural framework provides the foundation of the process. The predicted log is created using vertical sections of the nearby wells, which provide high confidence for determining depth and stratigraphic position of the geosteered well. The results give a better understanding of thickness variation in the horizontal part of the reservoir and maximize the reservoir contact (Sung, 2008). A new advanced methodology introduced in this study involves the creation of a dynamic structural framework model, from which horizontal well correlation is performed using real-time well logs and predicted logs that are generated from adjacent wells. The predicted logs are correlated to the LWD logs using anchor points and an interactive stretching and squeezing process that honors true stratigraphic thickness. Each new anchor point results in the creation of an additional control point that is used to build a more precise structural framework model. This new approach enables more rapid well log interpretation, increased accuracy and the ability to dynamically update the subsurface model during drilling. It also enables more efficient steering of the wellbore into the most productive zones of the reservoir. This study demonstrates how wells with over 10,000 feet of horizontal reservoir contact can be correlated in a real-time geosteering environment in a dynamic, efficient and accurate manner. The proposed process dramatically helps reduce the cost of drilling and the time it takes to dynamically regenerate accurate updated maps of the subsurface. It represents a major improvement in the understanding and modeling of complex, heterogeneous reservoirs by fostering a multi-disciplinary environment of cross-domain experts that are able to collaborate seamlessly as asset-teams. Both accuracy and efficiency gains have been realized by incorporating this methodology in the characterization of multi-stacked reservoirs.

APPLICATION OF A MULTIDIMENSIONAL DETERMINISTIC-STATISTICAL NUMERICAL CORRELATION MODEL TO REFINE THE STRUCTURE OF THE AS11 HORIZON OF THE ZAPADNO-KAMYNSKOYE FIELD

2021 ◽  
Vol 7 (3) ◽  
pp. 123-135
Author(s):  
Anatoly M. NIKASHKIN ◽  
Alexey A. KLIMOV
Keyword(s):  
Oil And Gas ◽  
Geological Structure ◽  
Correlation Model ◽  
Gas Reservoirs ◽  
Work Related ◽  
Correlation Models ◽  
Complex Geological Structure ◽  
Geophysical Information ◽  
Well Correlation ◽  
Clay Layers

One of the primary and significant tasks in the construction of geological models of oil and gas reservoirs and development facilities is the problem of correlation of productive layers. This task, as a rule, is reduced to the identification and areal tracing of presumably even-aged oil and gas strata, horizons, and layers characterized by clear boundaries between sand strata and clay layers overlapping them. The practice of work related to modeling the structure of oil and gas horizons, layers and strata indicates that the correlation is not always unambiguous. The ambiguity is especially noticeable when correlating strata characterized by a clinoform structure, one of the examples is the Achimov strata. The most reliable basis for well correlation is GIS materials and lithological features of the interlayers forming individual layers. Clay interlayers and clay strata separating productive deposits provide valuable information when choosing a correlation model in sedimentary sections. These interlayers are characterized by the greatest consistency in area and are most clearly displayed on geophysical diagrams by the nature of the drawings of GIS curves. However, even in this case, i. e. when using the entire accumulated volume of the most diverse lithological and field-geophysical information, the correlation models of the sections turn out to be different and often even opposite. In this paper, the authors had to face a similar situation when correlating the horizon AS11 of the Zapadno-Kamynskoye field. The paper describes a method for clarifying the position of the chops of the productive horizon of oil and gas deposits using a multidimensional deterministic-statistical numerical model of the correlation of sedimentary strata. The proposed approach allows us to uniquely determine the positions of the chops in the conditions of a complex geological structure of the object, high thin-layered heterogeneity. A concrete example shows the advantages of the proposed approach in comparison with the traditional one.

Automating Well Log Correlation Workflow Using Soft Attention Convolutional Neural Networks

2021 ◽  
Author(s):  
Aria Abubakar ◽  
Mandar Kulkarni ◽  
Anisha Kaul
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Convolutional Neural Network ◽  
Gamma Ray ◽  
Learning Algorithm ◽  
Machine Learning Algorithm ◽  
Well Log ◽  
Machine Learning Model ◽  
Well Correlation ◽  
Geological Formations

Abstract In the process of deriving the reservoir petrophysical properties of a basin, identifying the pay capability of wells by interpreting various geological formations is key. Currently, this process is facilitated and preceded by well log correlation, which involves petrophysicists and geologists examining multiple raw log measurements for the well in question, indicating geological markers of formation changes and correlating them with those of neighboring wells. As it may seem, this activity of picking markers of a well is performed manually and the process of ‘examining’ may be highly subjective, thus, prone to inconsistencies. In our work, we propose to automate the well correlation workflow by using a Soft- Attention Convolutional Neural Network to predict well markers. The machine learning algorithm is supervised by examples of manual marker picks and their corresponding occurrence in logs such as gamma-ray, resistivity and density. Our experiments have shown that, specifically, the attention mechanism allows the Convolutional Neural Network to look at relevant features or patterns in the log measurements that suggest a change in formation, making the machine learning model highly precise.

Comprehensive study of the geological structure Verkhneyakovlev deposits of the Tagul field in the process of justifications for operational drilling

2021 ◽  
pp. 85-97
Author(s):  
A. S. Titenkov ◽  
Yu. N. Utyashev ◽  
A. A. Evdoshchuk ◽  
V. A. Belkina ◽  
D. V. Grandov
Keyword(s):  
Complex Structure ◽  
Geological Structure ◽  
Reservoir Rock ◽  
Rock Properties ◽  
Capital Costs ◽  
Complex Geological Structure ◽  
Well Correlation ◽  
Effective Development ◽  
The Cost ◽  
Available Information

Currently, most of the fields being put into development are characterized by a complex geological structure, both in terms of section and in terms of plan. The solution of all geological tasks, including such important ones as the preparation of exploration projects, operation and effective development management, is impossible without creating models that reflect the main features of the variability of target parameters. The construction of adequate models of objects with a complex structure requires the involvement of all available information. The accuracy of the geological model is mostly determined by the accuracy of the well correlation. Paleosols are a new marker for the complex-built layers of the VAk-2 and VAk-3(1) of the Tagul field, which contributes to the validity of the correlation of the section of these layers. The reliability of the model was also improved by the use of the results of facies analysis. This analysis showed that the sedimentation of the studied objects includes channel and floodplain facies. Reservoir rock properties of these facies differ significantly. The updated model is characterized by a reduction in the oil-bearing area and the amount of reserves. The implementation of the model will optimize the project fund of wells and reduce the cost of well intervention. Economically, this means reducing capital costs and increasing the profitability of the project.

scholarly journals Immunofluorescence Assay for Detection of Human Metapneumovirus-Specific Antibodies by Use of Baculovirus-Expressed Fusion Protein

2005 ◽  
Vol 12 (1) ◽  
pp. 202-205 ◽  
Author(s):  
Nobuhisa Ishiguro ◽  
Takashi Ebihara ◽  
Rika Endo ◽  
Xiaoming Ma ◽  
Ryo Shirotsuki ◽  
...  
Keyword(s):  
Trichoplusia Ni ◽  
Respiratory Infections ◽  
Recombinant Baculovirus ◽  
Immunofluorescence Assay ◽  
Human Metapneumovirus ◽  
Specific Method ◽  
Serum Samples ◽  
F Protein ◽  
Hmpv Infection ◽  
Well Correlation

ABSTRACT Human metapneumovirus (hMPV) has recently been identified as an etiological agent of acute respiratory infections. The hMPV fusion (F) protein has been indicated to be a major antigenic determinant that mediates effective neutralization and protection against hMPV infection. We developed a new immunofluorescence assay (IFA) using Trichoplusia ni (Tn5) insect cells infected with a recombinant baculovirus-expressing hMPV F protein (Bac-F IFA). A total of 200 serum samples from Japanese people 1 month to 41 years old were tested for immunoglobulin G antibodies to hMPV F protein by Bac-F IFA. The results were compared with those of the conventional IFA based on hMPV-infected LLC-MK2 cells (hMPV IFA). The titers obtained by the two IFAs correlated well (correlation coefficient of 0.88), and the concordance of seroreactivities between the two IFAs was 91% (κ = 0.76). For 192 of the 200 serum samples, the titers obtained by the Bac-F IFA were equal to or higher than those obtained by the hMPV IFA. These results indicated that the Bac-F IFA was more sensitive than the hMPV IFA and that the majority of the antibodies detected by the hMPV IFA reacted with the hMPV F protein. The Bac-F IFA is a more reliable, sensitive, and specific method for the detection of hMPV antibodies than is the hMPV IFA.

Water-Shutoff Technique Extends Productive Life Cycle of Cretaceous Sandstone

2021 ◽  
Vol 73 (04) ◽  
pp. 51-52
Author(s):  
Chris Carpenter
Keyword(s):  
Life Cycle ◽  
Latin American ◽  
Petroleum Engineering ◽  
Productive Life ◽  
Fine Grain ◽  
Water Shutoff ◽  
Water Breakthrough ◽  
Sand Body ◽  
Well Correlation ◽  
Pulsed Neutron

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 199070, “Water-Shutoff Technique Extends the Productive Life Cycle of Cretaceous U Sandstone: The Iro Field Case in Ecuador,” by Luis Roberto Bailón, SPE, Ney Holger Orellana, SPE, and Santiago Villegas, Repsol, et al., prepared for the 2020 SPE Latin American and Caribbean Petroleum Engineering Conference, originally scheduled to be held in Bogota, Colombia, 17-19 March. The paper has not been peer reviewed. The water-shutoff technique is used in some wells of the U reservoir in the Iro field of the Oriente Basin in Ecuador as a remediation plan to restore production after an early water breakthrough. The production historical data, workovers, and sand-body correlation of wells are compared to understand reservoir behavior, shale-baffle-sealing continuity, the existence of different sand units, and the effect on production. Introduction The Iro field is in the south of Block 16. Production began in March of 1996. Iro is considered a mature field that produces heavy crude oil. The U sand-stone reservoir at Iro field is constituted by quartz grains subtransparent with fine grain sizes to medium, moderately classified, occasionally clay-like matrix. A thin limestone layer subdivides the U sandstone reservoir into two main stratigraphic units, Upper U and Lower U sandstone. Logging acquisition during the drilling campaign revealed heterogeneous sand-body deposition throughout the field. Depositional features of fluvial channels are developed from the base of the reservoirs, which are overlaid by sand bars. In addition, interbedded shale layers and baffles are present in the U reservoir, in some cases locally. However, the main shale layers are effective seals when they subdivide the Upper and Lower U sandstone units into two or more subunits. A good example is the shale layer that separates channels and bars in the Lower U sandstone unit. This identification was possible after the development of the well-drilling campaign, well correlation, and years of production behavior. Two subunits of the Lower U reservoir, Ui1 and Ui2, were classified as a result of the acquired data. Cased-Hole Logs (Pulsed Neutron) Given the maturity of the fields, during the last 2 years, a logging campaign of pulsed-neutron cased-hole logs has been performed. In the case of the Iro field, pulsed-neutron logs were run in six wells; three of these reached the Lower U reservoir. These three wells have a good correlation between the analog density and neutron curves of the cased-hole and the original openhole curves, providing certainty in the reading of the tool. The logging program obtained data of chemical-element spectra in capture and inelastic modes. This information was processed and analyzed to derive hydrocarbon saturation. In this way, by-passed oil can be identified as well as reservoir zones already drained by production of the same wells or by neigh-boring wells. Data in the Lower U reservoir show fluid movement.

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