FORMATION EVALUATION AND STATIC MODELLING IN THE WHEATSTONE GAS FIELD

2006 ◽  
Vol 46 (1) ◽  
pp. 161 ◽  
Author(s):  
P. Theologou ◽  
M. Whelan
Keyword(s):  
Experimental Design ◽  
Early Stage ◽  
Potential Range ◽  
Reservoir Properties ◽  
Gas Field ◽  
Formation Evaluation ◽  
Place Assimilation ◽  
Logging While Drilling ◽  
Realistic Information ◽  
The Impact

The Wheatstone gas discovery is located about 110 km north-northwest of Barrow Island in the Dampier Subbasin, northwest Australia. Gas was intersected within the AA sands of the Mungaroo Formation, and within a thin overlying Tithonian sand. Core was acquired through the base of the Tithonian sand and the upper section of the Mungaroo Formation.A combination of logging while drilling, wireline logging, core acquisition and special core analysis has formed the basis of an extensive formation evaluation program for Wheatstone–1. The acquisition of this dataset, and associated interpretation, has allowed Chevron to maximise its ability to characterise the reservoir early in the field’s history, and thereby has helped our understanding of the uncertainties associated with the formation evaluation and geological modelling of this fluvial system. Petrological studies indicate that reservoir properties and mineralogy are strongly correlated with the mean grain size of the formation. The mineralogy of the sands is relatively simple with minor quartz overgrowth, K-feldspar dissolution and kaolinite precipitation being the dominant diagenetic events. The better quality sands are generally devoid of significant amounts of clays such as illite-smectite. Within the Tithonian sand, more exotic mineral suites are present including glauconitic and phosphatic minerals.A comparison of resistivity data from wireline and logging while drilling (LWD) across cored and non-cored intervals through the Mungaroo Formation has revealed the impact that slow coring has had on formation filtrate invasion. It has been interpreted that the combination of slow rate of penetration, non-optimised mud properties, and coring assembly design resulted in deep invasion through cored intervals. Deep resistivity response through the invaded formation was subdued, and initially resulted in an underestimation of reserves. The incorporation of saturation information from capillary pressure data has provided for a more realistic view of gas-in-place.In this early stage of field appraisal, the generation of representative and fit-for-purpose reservoir models is somewhat difficult due to the small amount of available data existing away from the well. To provide realistic information on the potential range of gas-in-place for the field, experimental design methodology was incorporated into the modelling work-flow. Experimental design allows for rapid and comprehensive modelling of the possible range of the dependant variables, in this case GIIP (gas initially in place). Assimilation of geological analogues, formation evaluation and their inherent uncertainties has attempted to capture the range of GIIP in this world-class gas discovery.

MULTISCALE LOGGING WHILE DRILLING DATA INTEGRATION UNVEILED COMPLEX GEOLOGICAL SCENARIO WHILE GEOSTEERING

2021 ◽  
Author(s):  
Maurizio Mele ◽  
◽  
Filippo Chinellato ◽  
Andrea Leone ◽  
Francesca Arata ◽  
...  
Keyword(s):  
Real Time ◽  
Development Strategy ◽  
Reservoir Properties ◽  
Pilot Hole ◽  
Geological Interpretation ◽  
Reservoir Architecture ◽  
Logging While Drilling ◽  
Net To Gross ◽  
The Impact ◽  
Geological Scenario

The first Eni geosteering operation in Mexico was executed during the global COVID-19 crisis. The complex geology and the uncertainty related to this undrilled portion of the reservoir determined the employment of advanced Logging While Drilling (LWD) technology for real-time geosteering and a comprehensive geological interpretation. The target is an oil bearing sandstone reservoir, represented by deltaic front sands bars within an anticline structure on a salt core with faults and lateral heterogeneity. A sedimentological conceptual model was used to feed the 3D geological model, supporting a development strategy based on the geosteering of a horizontal well. The trajectory was designed within the best petrophysical properties interval to maximize production. The pre-drill risk analysis determined the need for a pilot hole to confirm structural setting, reservoir properties and fluid contacts to mitigate the associated uncertainties. The landing data acquisition strategy included standard LWD measurements and density images to optimize the wellbore inclination. The drain section was going to be geosteered with an Ultra-Deep Azimuthal Electromagnetic tool, dual-physics imager for oil-based mud systems and sourceless Density/Neutron technology. The pilot hole confirmed the pre-drill expected scenario but the LWD images and data interpreted while landing, revealed a more complex than expected target reservoir architecture. The detailed geological picture was completed while drilling the drain section. The multi-scale data (Reservoir Mapping information, Resistivity images, Logs, Seismic Interpretation and Pressure points) were integrated and exchanged 24/7 by experts through a commercial hub for team collaboration. A communication and information sharing protocol was customized to overcome the restrictions dictated by COVID-19 health emergency. The combination of acquired information and knowledge, unveiled a reservoir made of stacked clinoforms with internal geometries non-conformable with the general structural trend. Real-time geosteering with advanced technologies information, mitigated the impact of the unexpected complex subsurface setting. A total of 270 m were drilled inside the target, maximizing the drilled Net-to-Gross compared with the planned trajectory. Furthermore, the geological scenario reconstructed with multiscale LWD data, was exploited for a detailed 3D reservoir model update.

scholarly journals New Balanced Active Learning Model and Optimization Algorithm

2018 ◽  
Author(s):  
Xiaoqian Wang ◽  
Yijun Huang ◽  
Ji Liu ◽  
Heng Huang
Keyword(s):  
Experimental Design ◽  
Active Learning ◽  
Optimization Algorithm ◽  
Early Stage ◽  
Model Performance ◽  
Training Model ◽  
Learning Model ◽  
Model Quality ◽  
Learning Methods ◽  
The Impact

It is common in machine learning applications that unlabeled data are abundant while acquiring labels is extremely difficult. In order to reduce the cost of training model while maintaining the model quality, active learning provides a feasible solution. Instead of acquiring labels for random samples, active learning methods carefully select the data to be labeled so as to alleviate the impact from the redundancy or noise in the selected data and improve the trained model performance. In early stage experimental design, previous active learning methods adopted data reconstruction framework, such that the selected data maintained high representative power. However, these models did not consider the data class structure, thus the selected samples could be predominated by the samples from major classes. Such mechanism fails to include samples from the minor classes thus tends to be less "representative". To solve this challenging problem, we propose a novel active learning model for the early stage of experimental design. We use exclusive sparsity norm to enforce the selected samples to be (roughly) evenly distributed among different groups. We provide a new efficient optimization algorithm and theoretically prove the optimal convergence rate O(1/{T^2}). With a simple substitution, we reduce the computational load of each iteration from O(n^3) to O(n^2), which makes our algorithm more scalable than previous frameworks.

A Best Practice in Static Modeling of a Coalbed-Methane Field: An Example From the Bowen Basin in Australia

2015 ◽  
Vol 18 (02) ◽  
pp. 149-157 ◽  
Author(s):  
Ming Zhang ◽  
Yong Yang ◽  
Zhaohui Xia ◽  
Zehong Cui ◽  
Bin Ren ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Best Practice ◽  
Early Stage ◽  
Geographical Area ◽  
Static Model ◽  
Work Flow ◽  
Base Case ◽  
Reservoir Properties ◽  
Formidable Challenge ◽  
The Impact

Summary The development of a coalbed-methane (CBM) field in its early stage is often plagued by the lack of well control and the scarcity of geological data across a large geographical area. Therefore, constructing a representative static model to estimate the in-place volume presents a formidable challenge. In this paper, we propose a work flow to overcome this challenge and apply it to a CBM field in the northern Bowen basin of Australia. One may consider this work flow as a best practice for the following reasons. First, it makes use of data from various sources including cores, well logs, seismic interpretation, and topography. Second, it performs rigorous quality control on these data, such as depth shift and log normalization. Third, coal-ply division and correlation and subsequent structural modeling are based on three types of correlation: well-to-well, well-to-seismic, and well-seismic-geographic information system. Fourth, it establishes the low, base, and high trends for the most-important reservoir properties. Fifth, it constructs a base-case static model by combining the aforementioned structural and reservoir-property models. Sixth, it uses sensitivity analysis, which varies one reservoir parameter at a time, to rank the impact of reservoir parameters on in-place volume. Seventh, it uses uncertainty analysis that varies all reservoir parameters simultaneously to arrive at the P10, P50, and P90 in-place volumes and their corresponding static models that one can use for reservoir simulations to estimate the recoverable volumes.

The South Morecambe Field, Blocks 110/2a, 110/3a, 110/8a, UK East Irish Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 527-541 ◽  
Author(s):  
I. A. Stuart ◽  
G. Cowan
Keyword(s):  
Early Stage ◽  
High Reliability ◽  
Irish Sea ◽  
High Permeability ◽  
The South ◽  
Reservoir Properties ◽  
Gas Field ◽  
Reservoir Performance ◽  
Diagenetic History ◽  
First Time

AbstractThe South Morecambe Gas Field has been developed as a seasonal supply field to boost supplies to the National Transmission System at times of peak demand. This mode of operation has led to a requirement for exceptionally high reliability in all aspects of the development. This requirement has prompted the generation of an accurate and comprehensive geological model so that reservoir performance can be predicted as reliably as possible, and that wells can be drilled in optimum locations. The exceptional shallowness of the structure (crest at -2400 ft TVSS, GWC -3750 ft TVSS), coupled with the need to drain the reservoir cost-effectively and to minimize the risk of well interference has led to the use of slant drilling techniques for the first time in European waters. The field is located in the East Irish Sea Basin. The Triassic Sherwood Sandstone Gp forms the reservoir, and the Mercia Mudstone Gp provides the seal. The reservoir sands were laid down in a rapidly subsiding basin under continental semi-arid conditions, and comprise a complex interplay of major channel-fill sandstones, secondary channel-fill sandstones associated with non-channelized sheetflood sandstones, and localized, very high permeability (> 1000 md) aeolian and reworked aeolian sandstones. A vertical organization of these facies has been observed, with some intervals dominated by channel deposition, others by non-channelized deposits, due to periodic adjustments of the whole basin, and this has permitted the establishment of a reservoir zonation. A complex diagenetic history is recognized, with several phases of dolomite and quartz cementation. Differential compaction is also a major control on the disposition of reservoir properties. The greatest control on permeability (but not porosity) is platy illite which formed beneath a palaeo-GWC at an early stage in the growth of the structure, and which gives rise to a diagenetic layering of the reservoir into a high permeability Illite-Free Layer and a deeper, low permeability Illite-Affected Layer. The data presented herein is based upon the results of development drilling on South Morecambe.

KAJIAN DAMPAK KEBIJAKAN PENUTUPAN LOKALISASI TELEJU OLEH PEMERINTAH KOTA PEKANBARU

2017 ◽  
Vol 15 (2) ◽  
pp. 78
Author(s):  
M. Zainuddin
Keyword(s):  
Social Order ◽  
Qualitative Method ◽  
Negative Impact ◽  
Early Stage ◽  
Policy Research ◽  
Research Approach ◽  
Policy Content ◽  
The Government ◽  
Closure Policy ◽  
The Impact

This research to analyze the impact of closure policy Teleju brothel by Pekanbaru govermentin 2010. Guidelines for works are Pekanbaru Local Regulations No. 12 of 2008 on Social Order-liness. Closure this brothel inflicts positive and negative impact for society.The research wasconducted to obtain early stage formula for the government to take action against the prostitu-tion activities. This research uses policy research approach with a qualitative method, becausein prostitution activities and prohibition by goverment is an assessment that needs to be done byanalyzing documents and unstructured interview.The results showed that after the closing of the Teleju brothel have an impact on the deploy-ment of a prostitution and affect the economy of the surrounding residents. Government seeksto tackle prostitution in Pekanbaru by moving the brothel, conduct regular raids and providetraining. The effort is considered to be less than the maximum because the handling is not basedon the root of the problem and not programmed properly. There are several causes of failure ofgovernment to overcome the prostitution problem in Pekanbaru, including: policy content isless focus on the prostitution problem, the government did not proceeds with data, lack of finan-cial support, contra productive programs between local government with the police and TNI,and the policy object is difficult to be given understanding.

Fluoxetine Protects against Dendritic Spine Loss in Middle-aged APPswe/PSEN1dE9 Double Transgenic Alzheimer’s Disease Mice

2020 ◽  
Vol 17 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Jing Ma ◽  
Yuan Gao ◽  
Wei Tang ◽  
Wei Huang ◽  
Yong Tang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dendritic Spines ◽  
Dendritic Spine ◽  
Early Stage ◽  
Learning Ability ◽  
Middle Aged ◽  
Protein Levels ◽  
Spine Pathology ◽  
The Impact

Background: Studies have suggested that cognitive impairment in Alzheimer’s disease (AD) is associated with dendritic spine loss, especially in the hippocampus. Fluoxetine (FLX) has been shown to improve cognition in the early stage of AD and to be associated with diminishing synapse degeneration in the hippocampus. However, little is known about whether FLX affects the pathogenesis of AD in the middle-tolate stage and whether its effects are correlated with the amelioration of hippocampal dendritic dysfunction. Previously, it has been observed that FLX improves the spatial learning ability of middleaged APP/PS1 mice. Objective: In the present study, we further characterized the impact of FLX on dendritic spines in the hippocampus of middle-aged APP/PS1 mice. Results: It has been found that the numbers of dendritic spines in dentate gyrus (DG), CA1 and CA2/3 of hippocampus were significantly increased by FLX. Meanwhile, FLX effectively attenuated hyperphosphorylation of tau at Ser396 and elevated protein levels of postsynaptic density 95 (PSD-95) and synapsin-1 (SYN-1) in the hippocampus. Conclusion: These results indicated that the enhanced learning ability observed in FLX-treated middle-aged APP/PS1 mice might be associated with remarkable mitigation of hippocampal dendritic spine pathology by FLX and suggested that FLX might be explored as a new strategy for therapy of AD in the middle-to-late stage.

scholarly journals Effect of COVID-19 on Thoracic Oncology Surgery in Spain: A Spanish Thoracic Surgery Society (SECT) Survey

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2897
Author(s):  
Néstor Martínez-Hernández ◽  
Usue Caballero Silva ◽  
Alberto Cabañero Sánchez ◽  
José Luis Campo-Cañaveral de la Cruz ◽  
Andrés Obeso Carillo ◽  
...  
Keyword(s):  
Overall Response Rate ◽  
Early Stage ◽  
Care Delivery ◽  
Public Hospitals ◽  
Clinical Activity ◽  
Spanish Society ◽  
Lung Cancer Patients ◽  
Oncological Patients ◽  
Multiple Choice Questionnaire ◽  
The Impact

After the first wave of COVID-19, the Spanish Society of Thoracic Surgeons (SECT) surveyed its members to assess the impact of the pandemic on thoracic oncology surgery in Spain. In May 2020, all SECT members were invited to complete an online, 40-item, multiple choice questionnaire. The questionnaire was developed by the SECT Scientific Committee and sent via email. The overall response rate was 19.2%. The respondents answered at least 91.5% of the items, with only one exception (a question about residents). Most respondents (89.3%) worked in public hospitals. The reported impact of the pandemic on routine clinical activity was considered extreme or severe by 75.5% of respondents (25.5% and 50%, respectively). Multidisciplinary tumour boards were held either with fewer members attending or through electronic platforms (44.6% and 35.9%, respectively). Surgical activity decreased by 95.7%, with 41.5% of centers performing surgery only on oncological patients and 11.7% only in emergencies. Nearly 60% of respondents reported modifying standard protocols for early-stage cancer and in the preoperative workup. Most centers (≈80%) reported using full personal protective equipment when operating on COVID-19 positive patients. The COVID-19 pandemic severely affected thoracic oncology surgery in Spain. The lack of common protocols led to a variable care delivery to lung cancer patients.

scholarly journals Miniaturization and Automation of a Human In Vitro Blood–Brain Barrier Model for the High-Throughput Screening of Compounds in the Early Stage of Drug Discovery

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Blood Brain Barrier ◽  
Early Stage ◽  
Molecular Transport ◽  
Brain Barrier ◽  
Blood Brain ◽  
Cns Drugs ◽  
The Impact ◽  
The Brain

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.

scholarly journals Quality assurance of radiotherapy in the ongoing EORTC 1420 “Best of” trial for early stage oropharyngeal, supraglottic and hypopharyngeal carcinoma: results of the benchmark case procedure

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
J-J Stelmes ◽  
E. Vu ◽  
V. Grégoire ◽  
C. Simon ◽  
E. Clementel ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Early Stage ◽  
Prospective Trial ◽  
Similarity Index ◽  
Phase Iii ◽  
Current Phase ◽  
Hypopharyngeal Carcinoma ◽  
Transoral Surgery ◽  
Swallowing Function ◽  
The Impact

Abstract Introduction The current phase III EORTC 1420 Best-of trial (NCT02984410) compares the swallowing function after transoral surgery versus intensity modulated radiotherapy (RT) in patients with early-stage carcinoma of the oropharynx, supraglottis and hypopharynx. We report the analysis of the Benchmark Case (BC) procedures before patient recruitment with special attention to dysphagia/aspiration related structures (DARS). Materials and methods Submitted RT volumes and plans from participating centers were analyzed and compared against the gold-standard expert delineations and dose distributions. Descriptive analysis of protocol deviations was conducted. Mean Sorensen-Dice similarity index (mDSI) and Hausdorff distance (mHD) were applied to evaluate the inter-observer variability (IOV). Results 65% (23/35) of the institutions needed more than one submission to achieve Quality assurance (RTQA) clearance. OAR volume delineations were the cause for rejection in 53% (40/76) of cases. IOV could be improved in 5 out of 12 OARs by more than 10 mm after resubmission (mHD). Despite this, final IOV for critical OARs in delineation remained significant among DARS by choosing an aleatory threshold of 0.7 (mDSI) and 15 mm (mHD). Conclusions This is to our knowledge the largest BC analysis among Head and neck RTQA programs performed in the framework of a prospective trial. Benchmarking identified non-common OARs and target delineations errors as the main source of deviations and IOV could be reduced in a significant number of cases after this process. Due to the substantial resources involved with benchmarking, future benchmark analyses should assess fully the impact on patients’ clinical outcome.

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