INTERPRETATION OF LWD ACOUSTIC BOREHOLE IMAGE LOGS: CASE STUDIES FROM NORTH AMERICAN SHALE PLAYS

2021 ◽  
Author(s):  
Bo Gong ◽  
◽  
Ela Manuel ◽  
Youfang Liu ◽  
David Forand ◽  
...  
Keyword(s):  
Case Studies ◽  
Reservoir Characterization ◽  
Low Cost ◽  
Horizontal Wells ◽  
Drilling Fluids ◽  
Imaging Tool ◽  
Bedding Planes ◽  
Drilling Parameters ◽  
Acoustic Images ◽  
Formation Property

Logging-while-drilling (LWD) acoustic imaging technology emerged in the past few years as a low-cost solution to detect and characterize fractures in high-angle and horizontal wells. This type of imaging tool works in either water-based or oil-based drilling fluids, making it a competitive choice for logging unconventional shale wells, which are often drilled with oil-based mud. With high-resolution acoustic amplitude and travel-time images, fractures, bedding planes and other drilling-related features can be identified, providing new insights for reservoir characterization and wellbore geomechanics. The quality of LWD acoustic images however is directly affected by drilling parameters and borehole conditions, as the received signal is sensitive to formation property and wellbore changes at the same time. As a result, interpretation can be quite challenging, and caution needs to be taken to differentiate actual formation property changes from drilling-related features or image artifacts. This paper demonstrates the complexity of interpreting LWD acoustic images through multiple case studies. The examples were collected from vertical and horizontal wells in multiple shale plays in North America, with the images logged and processed by different service companies. Depending on the geology and borehole conditions, various features and artifacts were observed from the images, which can be used as a reference for geologists and petrophysicists. Images acquired with different drilling parameters were compared to show the effect of drilling conditions on image quality. Recommendations and best practices of using this new type of image log are also shared.

scholarly journals Imaging in Propeller Flap Surgery

2020 ◽  
Vol 34 (03) ◽  
pp. 145-151
Author(s):  
Shimpei Ono ◽  
Hiroyuki Ohi ◽  
Rei Ogawa
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Duplex Sonography ◽  
Computed Tomographic Angiography ◽  
Ease Of Use ◽  
Computed Tomographic ◽  
Imaging Tool ◽  
Preoperative Mapping ◽  
Flap Design ◽  
Tomographic Angiography

AbstractSince propeller flaps are elevated as island flaps and most often nourished by a single perforator nearby the defect, it is challenging to change the flap design intraoperatively when a reliable perforator cannot be found where expected to exist. Thus, accurate preoperative mapping of perforators is essential in the safe planning of propeller flaps. Various methods have been reported so far: (1) handheld acoustic Doppler sonography (ADS), (2) color duplex sonography (CDS), (3) perforator computed tomographic angiography (P-CTA), and (4) magnetic resonance angiography (MRA). To facilitate the preoperative perforator assessment, P-CTA is currently considered as the gold standard imaging tool in revealing the three-dimensional anatomical details of perforators precisely. Nevertheless, ADS remains the most widely used tool due to its low cost, faster learning, and ease of use despite an undesirable number of false-positive results. CDS can provide hemodynamic characteristics of the perforator and is a valid and safer alternative particularly in patients in whom ionizing radiation and/or contrast exposure should be limited. Although MRA is less accurate in detecting smaller perforators of caliber less than 1.0 mm and the intramuscular course of perforators at the present time, MRA is expected to improve in the future due to the recent developments in technology, making it as accurate as P-CTA. Moreover, it provides the advantage of being radiation-free with fewer contrast reactions.

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

2003 ◽  
Vol 20 (1) ◽  
pp. 557-561 ◽  
Author(s):  
A. Carter ◽  
J. Heale
Keyword(s):  
North Sea ◽  
Low Cost ◽  
New Technology ◽  
Horizontal Wells ◽  
Oil Price ◽  
3D Seismic ◽  
Rotary Drilling ◽  
Geological Society ◽  
Recoverable Reserves ◽  
Infill Drilling

AbstractThis paper updates the earlier account of the Forties Field detailed in Geological Society Memoir 14 (Wills 1991), and gives a brief description of the Brimmond Field, a small Eocene accumulation overlying Forties (Fig. 1).The Forties Field is located 180 km ENE of Aberdeen. It was discovered in 1970 by well 21/10-1 which encountered 119 m of oil bearing Paleocene sands at a depth of 2131 m sub-sea. A five well appraisal programme confirmed the presence of a major discovery including an extension into Block 22/6 to the southeast. Oil-in-place was estimated to be 4600 MMSTB with recoverable reserves of 1800 MM STB. The field was brought onto production in September 1975. Plateau production of 500 MBOD was reached in 1978, declining from 1981 to 77 MBOD in 1999.In September 1992 a programme of infill drilling commenced, which continues today. The earlier infill targets were identified using 3D seismic acquired in 1988. Acquisition of a further 3D survey in 1996 has allowed the infill drilling programme to continue with new seismic imaging of lithology, fluids and saturation changes. The performance of the 1997 drilling showed that high step-out and new technology wells, including multi-lateral and horizontal wells, did not deliver significantly better targets than drilling in previous years.In line with smaller targets, and in the current oil price environment, low cost technology is being developed through the 1999 drilling programme. Through Tubing Rotary Drilling (TTRD) is currently seen as the most promising way of achieving a step

scholarly journals Using Commercial Physical Activity Trackers for Health Promotion Research: Four Case Studies

2018 ◽  
Vol 20 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Gabrielle Turner-McGrievy ◽  
Danielle E. Jake-Schoffman ◽  
Camelia Singletary ◽  
Marquivieus Wright ◽  
Anthony Crimarco ◽  
...  
Keyword(s):  
Physical Activity ◽  
Health Promotion ◽  
Case Studies ◽  
Low Cost ◽  
Lessons Learned ◽  
Assessment Tools ◽  
Sensewear Armband ◽  
Research And Practice ◽  
Activity Trackers ◽  
Tracking Devices

Background. Wearable physical activity (PA) trackers are becoming increasingly popular for intervention and assessment in health promotion research and practice. The purpose of this article is to present lessons learned from four studies that used commercial PA tracking devices for PA intervention or assessment, present issues encountered with their use, and provide guidelines for determining which tools to use. Method. Four case studies are presented that used PA tracking devices (iBitz, Zamzee, FitBit Flex and Zip, Omron Digital Pedometer, Sensewear Armband, and MisFit Flash) in the field—two used the tools for intervention and two used the tools as assessment methods. Results. The four studies presented had varying levels of success with using PA devices and experienced several issues that impacted their studies, such as companies that went out of business, missing data, and lost devices. Percentage ranges for devices that were lost were 0% to 29% and was 0% to 87% for those devices that malfunctioned or lost data. Conclusions. There is a need for low-cost, easy-to-use, accurate PA tracking devices to use as both intervention and assessment tools in health promotion research related to PA.

Advanced Multi-Disciplinary Simulation Workflow for Well Placement, Hydraulic Fracturing and Production Optimization Applied to the Diyab Unconventional Play in Onshore UAE

2021 ◽  
Author(s):  
Hamid Pourpak ◽  
Samuel Taubert ◽  
Marios Theodorakopoulos ◽  
Arnaud Lefebvre-Prudencio ◽  
Chay Pointer ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
United Arab Emirates ◽  
Reservoir Characterization ◽  
Horizontal Wells ◽  
Production Optimization ◽  
Production Performance ◽  
Well Placement ◽  
Fully Integrated ◽  
Sector Model ◽  
The Impact

Abstract The Diyab play is an emerging unconventional play in the Middle East. Up to date, reservoir characterization assessments have proved adequate productivity of the play in the United Arab Emirates (UAE). In this paper, an advanced simulation and modeling workflow is presented, which was applied on selected wells located on an appraisal area, by integrating geological, geomechanical, and hydraulic fracturing data. Results will be used to optimize future well landing points, well spacing and completion designs, allowing to enhance the Stimulated Rock Volume (SRV) and its consequent production. A 3D static model was built, by propagating across the appraisal area, all subsurface static properties from core-calibrated petrophysical and geomechanical logs which originate from vertical pilot wells. In addition, a Discrete Fracture Network (DFN) derived from numerous image logs was imported in the model. Afterwards, completion data from one multi-stage hydraulically fracked horizontal well was integrated into the sector model. Simulations of hydraulic fracturing were performed and the sector model was calibrated to the real hydraulic fracturing data. Different scenarios for the fracture height were tested considering uncertainties related to the fracture barriers. This has allowed for a better understanding of the fracture propagation and SRV creation in the reservoir at the main target. In the last step, production resulting from the SRV was simulated and calibrated to the field data. In the end, the calibrated parameters were applied to the newly drilled nearby horizontal wells in the same area, while they were hydraulically fractured with different completion designs and the simulated SRVs of the new wells were then compared with the one calculated on the previous well. Applying a fully-integrated geology, geomechanics, completion and production workflow has helped us to understand the impact of geology, natural fractures, rock mechanical properties and stress regimes in the SRV geometry for the unconventional Diyab play. This work also highlights the importance of data acquisition, reservoir characterization and of SRV simulation calibration processes. This fully integrated workflow will allow for an optimized completion strategy, well landing and spacing for the future horizontal wells. A fully multi-disciplinary simulation workflow was applied to the Diyab unconventional play in onshore UAE. This workflow illustrated the most important parameters impacting the SRV creation and production in the Diyab formation for he studied area. Multiple simulation scenarios and calibration runs showed how sensitive the SRV can be to different parameters and how well placement and fracture jobs can be possibly improved to enhance the SRV creation and ultimately the production performance.

scholarly journals Awheel Along Europe’s Rivers: Geoarchaeological Trails for Cycling Geotourists

2018 ◽  
Vol 10 (1) ◽  
pp. 413-440
Author(s):  
Thomas A. Hose
Keyword(s):  
Roman Empire ◽  
Case Studies ◽  
Low Cost ◽  
Stone Age ◽  
Key Concepts ◽  
Review Study ◽  
Loess Deposits ◽  
River Valleys ◽  
Major Cycle ◽  
Current Provision

AbstractThis review study presents an overview of the potential for the development of geoarchaeological trails for leisure cyclists in Europe. It initially defines and discusses the underpinning key concepts and then examines the nature and main needs of leisure cyclists. It considers and recognises appropriate geo-interpretative themes, of geological/geomorphological and archaeological/historical interest, to employ in developing the trails. Noting that river valleys have long been natural route-ways for human expansion into Europe (as exemplified by the ‘Stone Age’ and the Roman Empire), and that many of today’s major cycle trails are beside rivers with loess deposits, a geoarchaeological geotourism strategy is considered in relation to them. Case studies of specific sites, from central southern England, the Middle Danube and Middle Rhine valleys, outline the current provision and the basis of the proposed trails. Finally, a common relatively low-cost, mixed media, geo-interpretative and promotional approach could generate the impetus to further develop the strategy is suggested.

Redevelopment of a Matured Multilayered Carbonate Offshore Field Through High Technology Horizontal and Multilateral Wells

2007 ◽  
Vol 10 (05) ◽  
pp. 453-457 ◽  
Author(s):  
Rajesh Kumar ◽  
S. Ramanan ◽  
J.L. Narasimham
Keyword(s):  
New Technologies ◽  
High Technology ◽  
Horizontal Wells ◽  
Development Stage ◽  
Scientific Data ◽  
Carbonate Reservoir ◽  
Western India ◽  
Drilling Fluids ◽  
Well Productivity ◽  
Offshore Field

Summary Oil productivity from Mumbai High field, an offshore multilayered carbonate reservoir, increased significantly through the implementation of a major redevelopment program. Geoscientific information available from approximately 700 exploratory and develop- ment wells drilled in the field during nearly 25 years was incorporated during geological and reservoir simulation modeling of the field. High-technology drilling (viz. horizontal/multilaterals for the new development wells) was adopted on field scale to effectively address typical complexity of the layered carbonate reservoirs. Since the commencement of the project in 2000, approximately 140 new wells were drilled, mostly with horizontal and multilateral drainholes. Besides these, more than 70 suboptimal producers were also converted as horizontal sidetracks under brownfield development. The horizontal sidetracks were drilled as long-drift sidetrack (LDST), extended-reach drilling (ERD), LDST-ERD, short-drift sidetrack (SDST), and medium-radius drainhole (MRDH) types of wells through the application of innovative and emerging drilling technologies with nondamaging drilling fluids, whipstocks to kick off sidetrack wells, rotary-steering systems, and expandable tubulars to complete horizontal sidetracks in lower layers. With the implementation of this project, the declining trend was fully arrested and a significant upward trend in production has been established. Introduction The field redevelopment process requires the intergration of reservoir-development strategies, facility options, and drilling and production philosophies to maximize oil and gas recovery from a matured field. A significant number of case studies are available on mature field revitalization using a multidisciplinary team concept, exhaustive geo-scientific data analysis, and new drilling technologies (Chedid and Colmenares 2002; Clark et al. 2000; Dollens et al. 1999; Kinchen et al. 2001). Advancements in drilling and completion technology have enabled construction of horizontal wells with longer wellbores, more-complex well geometry, and sophisticated completion designs. Horizontal wells provide an effective method to produce bypassed oil from matured fields. In the early 1980s, this technology was in the development stage and was used in limited applications. By the 1990s, the technology had matured, and its acceptance in the industry had increased significantly. Performance of horizontal/multilateral wells, risk assessment of horizontal-well productivity and comparison of horizontal- and vertical-well performance in different fields is available in literature (Babu and Aziz 1989; Brekke and Thompson 1996; Economides et al. 1989; Joshi 1987; Joshi and Ding 1995; Mukherjee and Economides 1991; Norris et al. 1991; Vij et al. 1998). A significant number of horizontal/multilateral development wells were drilled as a part of redevelopment of Mumbai High, a matured multilayered carbonate offshore field in Western India. The details of new technologies applied and performance of these new high-technology wells are presented in this paper. Besides comparison of well productivity of horizontal and conventional sidetrack wells, this paper presents some technical issues faced.

scholarly journals Lumped damage mechanics as a diagnosis tool of reinforced concrete structures in service: case studies of a former bridge arch and a balcony slab

2021 ◽  
Vol 15 (58) ◽  
pp. 21-32
Author(s):  
Rafael Cunha ◽  
Camila Vieira ◽  
David Amorim
Keyword(s):  
Reinforced Concrete ◽  
Case Studies ◽  
Damage Mechanics ◽  
Low Cost ◽  
Concrete Structures ◽  
Structural Condition ◽  
Numerical Analyses ◽  
Engineering Practice ◽  
Reinforced Concrete Structures ◽  
Diagnosis Tool

Reinforced concrete structures may need repair in order to ensure the designed durability. Such necessity vary in cause and effect, but the structural diagnosis serves as the basis for adopting intervention measures. The assessment of the structural condition usually is made in loco, but sometimes numerical analyses are required as a low cost and effective preliminary diagnosis. In general, numerical analyses use hundreds or thousands of finite elements and nonlinear theories that are not often used in engineering practice. As an alternative, lumped damage mechanics (LDM) uses key concepts of classic fracture and damage mechanics in plastic hinges throughout well-known quantities such as ultimate moment and cracking moment. Such theory describes the concrete cracking by a damage variable, which can be used as a diagnosis criterion. Therefore, this paper presents LDM as a diagnosis tool to analyse actual structures. The case studies presented in this paper are a former bridge arch tested in China and a balcony that collapsed in Brazil. The results show that LDM numerical response of those structures are quite close to laboratory observations (former bridge arch) and in loco measurements (balcony).

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