bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controls on Petrophysical Properties of the Mauddud Formation, Bahra and Sabriyah Fields, Kuwait
Authors: Behbehani Sayed , Hollis Cathy 
Published: December 2015

AbstractThe petrophysical properties of reservoirs represent several factors such as reservoir quality and volume of oil saturation (PHI, PERM and SW). The relationship between these factors is complementary; migration and trapping of oil is critical to reservoir quality preservation and it is often compromised by closure of the structure, quality of the seal and tectonic activity. In Kuwait, the Mauddud Formation in Bahra Field (BAMA) does not show a sustainable oil production, unlike the Mauddud Formation in Sabriyah Field (SAMA), although both fields are neighboring and separated only by a saddle. Well data reveals a considerable reservoir complexity that distinguishes BAMA from SAMA, which cannot be easily ascribed to facies variability. Geological data (seismic, wireline logs, core and thin sections) indicates four main differences in BAMA compare to SAMA. First, general stratigraphic thinning of carbonate sequences due to its palaeo-proximal position that made it more susceptible to erosion and increased clastic supply and, secondly, a sandier seal rock. Thirdly, there is a degradation of reservoir quality where the average oil saturation and the porosity are 50% and 15% respectively, compared to 90% and 20% In SAMA. Finally, three fault orientations occur in BAMA including a distinct E-W trend, that does not observed in SAMA. Three main possible hypotheses postulated in this study are based on early results.Cementation by meteoric phreatic cements occluded the porosity in BAMA before the arrival of oil. The fresh water penetrations was facilitated by the sandier seal and proximal paleo- environment in BAMA.Onset and partial growth of the trapping structure in SAMA, allowed an earlier oil expulsion to become trapped, retaining secondary porosity, whilst oil bypassed BAMA traps due to later structural growth.The E-W faults in BAMA were responsible for oil migration vertically by breaching the seal rock. The leakage was followed by an influx burial fluids which re-activated cementation in BAMA that was arrested for a short period by the arrival of oil.
Wellhead and X-Mas Tree Seal Integrity Challenges in Qatargas OPCO
Authors: Das Prashun Kumar , Jaiswal Navin Prakash 
Published: December 2015

Abstract
This paper is about Wellhead and X-Mas Tree Seal Integrity issues and the innovative approach adopted by Qatargas (QG) to deal with them. It provides a brief about measures taken to minimize the risk for operating wells with Wellhead and X-Mas Tree Seal integrity issues.
QG started production in 1996 and is now one the premier LNG company in the world. After six years of its initial start-up, results of Wellhead and X-Mas Tree Seal tests indicated possible Wellhead and X-Mas Tree seal integrity issues. At that time this matter was thought to be manageable.
In 2011, a Peer Review was arranged between QG, its Shareholders, and the Original Equipment Manufacturer (OEM) to analyze the current risk profile of the wells and decide on an action plan. Retesting of wellhead seals was carried out at the end of 2012. Instead of using the conventional approach, new techniques were applied to test the seals. The applied seal testing method was significantly different than the conventional test method, which eliminates the probability of damaging seals while testing. This paper will also highlight the difference in the testing approach. Detailed analysis of test result indicated that the seal integrity issues aggravated over time. Peer Reviews and root cause failure analysis (RCFA) were conducted to understand the cause of many failures.
A wellhead design change was proposed to rectify the seal integrity issue and to eliminate the identified root cause; this paper contains details of internal design changes. The paper also covers the details of Finite Element Analysis (FEA) and RCFA. It also covers details of all possible solutions that were thought to be effective initially, but later on were recognized as short term solutions.
Engagement of High Potential Employees Ensures Retention and Sustainable Knowledge Transfer in a Cyclical Industry
Authors: Ash P. 
Published: December 2015

Abstract
Fluctuations in commodity pricing and supply and demand are inherent to the upstream oil and gas market. In recent years, other emerging factors, often onset by these fluctuations, have begun to contribute to the complexity within the human capital component of the industry. Business and human resource leaders are forced to make increasingly difficult decisions regarding personnel capabilities, utilization, and reduction in attempt to align the enterprise in a briskly changing landscape.
With the current knowledge gap between entry to mid-career level and seasoned personnel, coupled with the volatility in commodity prices and organizations' need to react, learning and human resource professionals must navigate a dynamic challenge with personnel: engage high potential, talented employees and ensure their retention in order to create personal career satisfaction, thus securing a sustainable knowledge transfer to developing professionals. This challenge amplifies the need for a diagnostic approach to workforce planning and management in upstream oil and gas organizations.
Traditional talent management tools, such as learning programs, competency initiatives, and career paths, offer proven methods for the employee and organization to maneuver industry cycles. However, as the cycle shifts under the pressure of new challenges, the static and rigid nature of traditional approaches must be examined and refined in order to provide a sustainable talent pipeline. This paper will examine a case study of a highly visible and well-defined talent management framework that provides management with a strategic and calculated method for assessing employee capability against market compatibility in order to make sound decisions in a time of restructuring. Additional research will demonstrate the positive impact of implementing a competency-based, career progression structure to meet business needs, motivate employees, and ensure knowledge retention within an organization.
Finally, it will introduce a brief overview of leveraging action-learning events to incite employees and optimize training resources, such as: intentional mentoring, on-demand learning, and core competency assessment. The paper will establish the value of combining these efforts with career development into a cohesive framework that creates a sustainable, transparent roadmap to shape and facilitate highly engaged, visible, and proficient professionals with the flexibility and agility to withstand future cycles.
An Integrated Full-Field Development of a Giant Mature Field using CO2 EOR
Authors: Jia Liping , Kumar Navanit , Kumar Kamlesh , Nicolo Micah , Dexcote Yann , Peyret Aymeric 
Published: December 2015

Abstract
The giant field is a geologically complex, faulted anticlinal structure trending east-west, with dips ranging from 0 to 60 degrees. After the current waterflood operations are completed, it is estimated that about 2/3 of oil originally in place will be left behind unrecovered. The combination of light oil gravity and relatively high reservoir pressures makes these reservoirs good candidates for miscible CO2 EOR. There are separate waterflood developments that have been identified as candidates for CO2 EOR. Results of the CO2 pilot provide further encouraging results that show better than expected CO2 injectivity and vertical sweep than waterflood and good displacement of the remaining oil saturation.
The subsurface team successfully used design of experiments to manage uncertainties in history matching and production forecast. Multiple static realizations honoring the key geological uncertainties were built. Based on ranking criteria developed, there were three static realizations chosen for history matching; that resulted in good history matches obtained for five different realizations. The history match model includes all the 500 wells, 70 years of historical production and water injection. All the history matches were within uncertainty ranges and were technically assured for use in CO2 EOR forecasting. Sector modeling was used to identify and rank different subsurface uncertainties and decisions. Experimental design was used to manage the uncertainties remaining after history match. Hundreds of realizations were simulated that incorporated several integrated development decisions such as injection scheme, development sequence, well spacing, completion strategy and well orientation. Simulation results for all the realizations (with different levels of heterogeneity) indicate that the range of recovery factors varies from 10% (P10) to 24% (P90). The simulated forecasts were also benchmarked against limited analog fields. The production curves are then upscaled to the whole field using a dimensionless curves approach in WellSpring. A methodology to integrate inputs from multiple disciplines (surface, subsurface, wells and CO2 source) was developed to different integrated filed development options.
The complexity, depth, and compartmentalization of the field create challenges that affect all aspects of the CO2 EOR field development including: scope for CO2 recovery, flood design options, data gathering needs, integration with existing waterflood, utilization of existing comingled wells, surface facilities and subsurface modeling for realistic production forecasting. Our work focuses on the selection of field development concepts and determining the economic viability whilst incorporating the best practices and lessons learned from the CO2 EOR industry to ensure top quartile performance.
Fracture Characterization by Integrating Seismic-Derived Attributes including Anisotropy and Diffraction Imaging with Borehole Fracture Data in an Offshore Carbonate Field, United Arab Emirates
Authors: Liu Enru , Johns Mary , Zelewski Gregg , Burnett William A. , Wu Xianyun , Zhang Jie , Molyneux Joe , Skeith Gene , Obara Tomohiro , El-Awawdeh Raed , Sultan Akmal , Al Messabi Abdulrahman 
Published: December 2015

AbstractIn this paper, we present a case study of fracture characterization by integrating borehole data with a variety of seismic attributes in a carbonate reservoir from a giant offshore field, United Arab Emirates. The objectives are to determine to what extent seismic data may be confidently used for mapping spatial distributions of subtle faults and fracture corridors in the reservoirs and to better understand the distribution of overburden anomalies (karsts, high impedance channels) for field development planning. Borehole data used in our study include information from core descriptions (fracture density and orientations), image logs, cross-dipole shear-wave anisotropy analysis, and dynamic data (well testing, PLT, tracer, and mud-loss). The seismic attributes include standard and advanced post-stack geometrical attributes; pre-stack seismic azimuthal AVO attributes, and recently developed pre-stack diffraction imaging. We find that there are common features that can be identified in different attributes, and the differences may indicate different scales of fractures. We also observe a qualitative correlation in the area of history match challenges and high anisotropy magnitude, where seismic anisotropy can identify relatively high fracture intensity regions/zones instead of pinpointing individual fractures and complements other attributes as differences do exist between seismically identified fracture zones and well data due to overburden anisotropy, resolution and sampling issues (which are addressed using the synthetic modeling approach). Diffraction attributes have revealed more detailed geological features in overburden (e.g. karsts) and reservoirs (e.g. lineaments) than in reflection data and a comparison with mud loss data in the shallow zones looks promising with a good correlation between mud loss and collapsed features. This work has provided an improved understanding of the applicability of the using multi-seismic attributes for fracture characterizations in carbonate reservoirs.
LIDAR Technology Application for Outcrop to Subsurface Reservoir Study of Oman Interior
Authors: Shahar Suhaileen , Dawing Sudirman , Jones R. 
Published: December 2015

AbstractThe Amin sandstone is a primary reservoir target of the Haima Supergroup (Vendian -Cambrian) for a Tight Gas Play for the Non-Associated Gas exploration in the Fahud Salt Basin, onshore Oman. Recent development in Tight Gas exploration in Oman have focused on possible fractured reservoirs of the Haima Supergroup. However, uncertainty remains in mapping and modeling of deformation styles of the various Haima lithologies, under the influence of regional and localised tectonic evolution. Quantification of the late structural evolution of the Oman Mountain orogeny in the Late Cretaceous were taken into consideration, which may introduce fracturing or possibly reactivates earlier structures of these Vedinian-Cambrian rocks.Multi-disciplinary fieldwork was carried out, with the following overall aims: (1) to understand the effect of mechanical rock properties on deformation styles of the Amin Fm. (Haima Supergroup) and the Buah Fm. (Huqf Supergroup) and (2) to develop understanding of potential fractured plays in the Fahud Salt Basin area. Due to limitation of number of available days for fieldwork, surface LIDAR acquisition was utilised to expedite fracture measurements on selected outcrops. We focused upon the Haushi-Huqf Uplift 300km south of Muscat due to presence of good quality outcrops of Amin and Buah formations. LIDAR acquisition was carried out over three major localities: a) Locality 1: Wadi Sumayinah, b) Locality 2: 5km SE of Wadi Sumaynah and c) Locality 3: the Buah Anticline.In parallel to surface geology studies, a much wider regional geophysical interpretation was carried out to investigate possible correlation of structural styles seen at the outcrops to our area of interest which lies approximately 200km northwest of the Huashi-Huqf Uplift. For this regional evaluation we have utilised gravity data and satellite imagery, proprietary regional 2D seismic and 3D seismic to improve our interpretation of major structural lineaments in the subsurface and possible correlation to measured surface geology.Several relevant, nearby published discoveries were used as analogues of fractured reservoirs in the subsurface as calibration of our observations and interpretations.We observed over a wide area of ~ 200-300km radius, that the main structural orientations seen in outcrop can be correlated to the area of exploration interests. Similar fracture orientations can be observed and compared to the analogue discoveries of the fractured Aptian limestone; these observations further support the likelihood of reactivation of older reservoir structions in response to later tectonic events.From this exercise we found many possibilities to improve surface geological data in supporting subsurface E&P activities. Although we acknowledge that issues of scale still remain, the effort to find better methods to integrate and exploit the value of surface geological analogues as an effective hydrocarbon prospecting tool should be fully harnessed.
Integrating Complementary Information in Full Waveform Inversion: Insights and a Practical Case Study
Authors: Silva Nuno V. da , Privitera Antonio , Ratcliffe Andrew , Conroy Graham 
Published: December 2015

Abstract
Full waveform inversion (FWI) now plays an increasingly relevant role in oil and gas exploration to determine high-resolution velocity models for improved seismic imaging and interpretation. This is especially true in regions of the Earth that are probed by diving waves. These realistic velocity models are important in areas where the subsurface is characterized by complex structures. This work discusses strategies for constraining these models with a priori information from sonic logs. We show an application of multi-parameter FWI on a Central North Sea dataset, where we compare results with and without including sonic log constraints in the inversion.
Recent Advances in Fiber Optic Technology for In-Well Production and Injection Profiling
Authors: van der Horst Juun 
Published: December 2015

AbstractIn the past decade, Fiber-Optic (FO) based sensing has opened up opportunities for in-well reservoir surveillance in the oil and gas industry. Distributed Temperature Sensing (DTS) has been used in applications such as steam front monitoring in thermal development projects and injection conformance monitoring in waterflood development projects using warmback analysis and FO-based pressure gauges are deployed commonly. In recent years significant progress has also been made to mature other, new FO-based surveillance methods such as the application of Distributed Strain Sensing (DSS) for monitoring reservoir compaction and well deformation, multidrop Distributed Pressure Sensing (DPS) for fluid level determination, and Distributed Acoustic Sensing (DAS) for geophysical and production/injection profiling. For the latter application, numerous field surveys were conducted to develop evaluation algorithms to convert the DAS noise recordings into flow rates from individual zones.In this paper we present an overview of recent advances in FO-based methods such as DAS, DTS, and DSS for the application of production and injection surveillance. From field examples acquired by Shell and its affiliates it is clear that FO-based flow monitoring provides a powerful addition to the standard surveillance toolkit and in some cases is even the preferred way of surveillance because of its unique advantages.
Ultrasound-Guided Minimally Invasive Surgery for Achilles Tendon Rupture: Preliminary Results
Authors: Wang Chen-Chie , Chen Pei-Yu , Wang Ting-Ming , Wang Chung-Li 
Published: December 2015

Background: Many surgeons prefer surgical repair for Achilles tendon ruptures in an attempt to reduce the risk of rerupture. To minimize wound complications, the use of minimally invasive surgery has become more popular recently. In line with this, the use of ultrasound to guide Achilles tendon repair is reported in this study. Methods: From March 2005 to January 2008, 23 patients with Achilles tendon rupture were repaired by the same surgeon. The ages of the patients ranged from 19 to 67 years old, with an average of 43 years old. The repair of the Achilles tendon was achieved through a stab wound under the guidance of ultrasonography. A control group consisted of 25 patients who received traditional open Achilles tendon repair. Results: The average operation time was 52 minutes, and the average wound size was 1.1 cm. The short leg cast was removed 4 weeks after the surgery, and serial casting was used for another 3 to 4 weeks. The postoperative AOFAS ankle-hindfoot scores were 98.7 in the experimental group, 96.5 in the control group with no significant difference. The rates of local infection, stiffness of the ankle, pain of the scar and sural nerve injury were better in the experimental group than in the control group with significant difference. Conclusions: Ultrasound-guided surgery was a good choice due to its availability and real-time soft tissue visualization. It can further minimize the size of the surgical wound. Our method has the potential to achieve reliable results. Level of Evidence: III, Comparative Case Series III
Magnetic Resonance Imaging Features of Osteochondral Lesions of the Talus
Authors: Hembree Walter C. , Wittstein Jocelyn R. , Vinson Emily N. , Queen Robin M. , LaRose Connor R. , Singh Kush , Easley Mark E. 
Published: December 2015

Background: Osteochondral lesions of the talus (OLT) traditionally have been thought to occur anterolaterally or posteromedially. Recent studies utilizing magnetic resonance imaging (MRI) have questioned this teaching. The purpose of this study was to use MRI to describe the location, frequency, and morphology of OLT and determine if any correlations exist between lesion location and other data points. Methods: The location, frequency, and size of OLT based on a nine-zone grid were recorded on 77 MRI examinations. Lateral ligaments were inspected for evidence of injury. Stability of the lesions was assessed based on four MRI criteria: presence or absence of cartilage defects, edema-like signal abnormality, T2 bright rim, and/or subchondral cysts. Demographic data including patient age, injury mechanism, and chronicity were recorded. An ANOVA model was used to determine if statistical differences existed between lesion size and location. Pearson correlation coefficients were used to examine any association between lesion location and demographic data. Results: Most of the lesions were located medially and centrally on the talar dome (54.5%), with the second highest frequency found laterally and centrally (31.2%). With the numbers available there was no statistical difference between the size of the lesions based on location. No strong correlations were found between lesion location and demographic data. Conclusion: This study refutes traditional teachings regarding the location of OLT and supports recent studies showing that most lesions are located medially and centrally on the talar dome. Level of Evidence: IV, Retrospective Case Series
Metatarsal Lengthening by Callotasis in Adults with First Brachymetatarsia
Authors: Hwang So-Min , Song Jennifer Kim , Kim Hui-Taek 
Published: December 2015

Background: Brachymetatarsia is a rare clinical entity that presents a challenging problem for surgeons. One-stage lengthening with an autologous bone graft has been preferred for metatarsals that require a limited lengthening. With a gradual lengthening of metatarsals, callus distraction (callotasis) can achieve a greater length gain and a concomitant lengthening of the soft tissue. This article presents results of callotasis for adults with first brachymetatarsia. Methods: The outcomes of nine cases of first brachymetatarsia in five adult patients who underwent metatarsal lengthening by callotasis between March 1999 and February 2005 were retrospectively reviewed and analyzed. Results: The average length gain was 16.4 mm and the average lengthening percentage was 43.7%. In addition, the average healing index was calculated as 3.8 months/cm, which was higher than that reported previously in the fourth brachymetatarsia. Conclusion: It was concluded that the period of bony consolidation following callotasis is longer in the first brachymetatarsia than in the fourth brachymetatarsia. Presumably, this might be because of the anatomically larger osteotomized cut surface and its weight-bearing function. Level of Evidence: IV, Retrospective Case Series