bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-Time High-Resolution LWD Images Used to Navigate a Carbonate Reservoir
Authors: Janwadkar Sandeep Shashikant , Murell Paul , Thomas Mark 
Published: March 2015

Abstract
The Permian basin of West Texas is one of the most mature and prolific oil provinces in the US, and continuously evolves in its production potential via the drilling of horizontal wells. A vital element to accelerate ROI is to accurately place the wellbore in the target formation. Determining and identifying the zone of interest within the carbonate interval and then navigating within it with conventional LWD technology has become a major challenge. To overcome these challenges, real-time high-resolution LWD images were proposed. Azimuthal gamma ray and multiple propagation resistivity measurements were used to determine bed dip, correlate position within the reservoir and indicate formation porosity variations. Advanced LWD imaging tools provide visual confirmation of steering up and down within the reservoir and identify structural information, porosity changes, rock type, faults and the location, density and type of fractures. This paper provides examples of reservoir navigation techniques along with the increased precision provided by imaging tools. Previously undetected faults, brecciated intervals, and fractures are identified. This enables a more precise completion design that reduces risk and increases production. Using this method, the percentage of the lateral interval in zone was increased to 100% from 77% in an offset well. Images of lateral variations in the formation will be presented. This information was used to optimize the completion design and is invaluable in the planning of future wells. LWD images are used to more efficiently drain the reservoir by providing the necessary information to stay in the target zone during longer intervals and assist completion optimization. LWD images can also be used to help explain production variances commonly observed between wells targeting the same interval.

Geological Background
The Permian Basin is a sedimentary basin largely contained in the western part of Texas and the southeastern part of New Mexico (Fig. 1). It is so named because it has one of the world's thickest deposits of rocks from the Permian geologic period.
The Permian Basin was deposited from Ordovician through Mississippian time, and is deepest just west of Midland. It was uplifted at the end of the Devonian and early Mississippian periods. Tectonic activity at the end of the Mississippian period created the Midland Basin to the east, the Delaware Basin to the west and the Val Verde Basin to the south. During the Pennsylvanian and Wolfcamp periods, the basin was favorable to reef growth and the building of shelf margins on the edges of the Delaware and Midland basins. The last major geological development was the Permian Reef Complex, which developed on the border of the Delaware Basin. (J. Michael Party 2012)
Development and Application of Horizontal Well Drilling Technologies with Liaohe Oilfield's Characteristics
Authors: Xun Chen 
Published: March 2015

Abstract
On September 13, 2011, China Petroleum Daily published an article titled '1,000 Horizontal Wells Support the Stable Production of 10Mt/y of Oil in CNPC Liaohe Oilfield' on the front-page. This marked a historical breakthrough in large-scale application of horizontal wells in Liaohe Oilfield. Rather than deliberately pursuing the cutting-edge technology, the development and application of horizontal well drilling technology was based on practical experience of oil & gas exploitation, predominantly lead by conventional horizontal well technology. The development and application of horizontal drilling technology also focused on solving the technological difficulties of multilateral and complex wells. Extensive efforts were made to develop sidetracked horizontal wells in the exploited zone. In the development and application process, ten major horizontal well drilling technologies with Liaohe's characteristics were developed, which included MRC fishbone well, SAGD paired horizontal well, multilateral well, complex well, sidetracked horizontal well, and horizontal & underbalanced drilling integrated technologies.
In addition to an overview of horizontal well drilling technologies with Liaohe's characteristics, the paper also presents achievements of industrial application of horizontal well technology in many areas, such as new block development, heavy oil development mode transformation, secondary development of old oilfields, evaluation and development of hard-to-recover reserves, progressive exploration etc.
A Comparative Analysis of the Contractual and Regulatory Framework of the Oil Industry: Global Changes and Practices
Authors: Shivsulabh Nambiar Aiylath Kutteri , Singh Arshdeep 
Published: March 2015

Abstract
Inception and General Principle of the paper:
The oil and gas industry is an ever shifting paradigm with new happenings which is not only represented through its exploration practices, the inception of new technology, the corresponding implementation of this technology, but is also represented by subsequent and corresponding changes in the techno legal framework as well, which is also needed to be fully appreciated in order to understand the global demand of petroleum and its subsequent by-products which clearly are the driving force of any economy today, hereby enabling even the weakest of countries to determine the political, economic and trade related fate of other Developed countries.
Application and Significance of the Proposed research paper:
The research paper attempts at a comparative analysis between the various contractual regimes with respect to oil exploration and the subsequent production between developed countries such as USA etc. and developing countries such as China, India while also tracking the subsequent changes and global practices in other oil rich countries such as Iraq, UAE etc. who invariably shape the oil and petroleum needs of various countries.
During this course we shall subsequently study successful operations engaged in various models by different countries such as Consessional models, Production sharing arrangement, joint ventures, Service agreements etc., Hereby manifesting and displaying various approaches taken by carious countries, analyzing the same and understanding certain constraints which can/could have been rectified.
Wag Injector Wells: How Intelligent Completion Technology Could Impact on Project Economics
Authors: Di Vincenzo Stefano 
Published: March 2015

Abstract
Nowadays WAG (water alternate gas) injector is considered a new frontier for subsea field with injectors or disposal wells in order to minimize CAPEX and obtain same benefits on field substain.
Looking forwards to forthcoming subsea development, to implement this technology has been considered a must in order to reduce the number of wells dedicated to injection and reduce subsea facilities layed for injection both gas and water. Company is going to develop field in Angola and Nigeria, where oil has different characteristics but with the same constrains related to reservoir pressure maintenance.
This abstract shall consider a study performed by headquarter related to the possible scenario accepting WAG injection using intelligent completion technology and the relative risk analysis. This technology for the company is considered a key choice in order to complete, partialize and control flowing in different layers, with different pressures and different characteristics. Conscious of this ability engineering center decided to move in this direction (more or less one years ago in 2010) and started a dedicated detailed study to consider Angolan field.
The field have a water depth and environment with 1,500 - 2,000 m of water depth.
The goal of the project will be achieved a cut off 50% of the CAPEX related to injectors in both fields, at the same time considering also interface with subsea facilities and surface facilitites. Abstract aims to show what is the impact in terms of economic, evaluated on this project, beginning by base case of injectors dedicated for each level, to final project approved and actually in execution. Terms of comparison will be the delta CAPEX, NPV and IRR of both projects.
Technologies Unlocking Unconventional Gas Resources - Field Case Studies from Northern America and China
Authors: Yu J. , van Gisbergen S. , Dwan S.F. , Yuan R. , Hackbarth C. , Shi S. , Lambrecht J. 
Published: March 2015

Abstract
This paper highlights selected subsurface technologies that are the key contributors to the success in exploring and developing unconventional resources in North America and now elsewhere. Illustrative field examples are presented which have applied these technologies, along with their integrated workflows and best practices, covering a) advanced seismic solutions for unconventionals sweet-spotting; b) improved modelling and numerical simulation software for better hydrocarbon charge prediction and EUR/production forecasts; and c) advanced tools for real-time downhole fracture/production monitoring. Successful field case studies demonstrate how applying advanced techniques may result in reducing lifecycle costs, maximising recovery and minimising environmental impacts in the process of exploring and developing unconventional gas resources. Rapid sharing and replication of new technologies and best practices globally (e.g. from North America to China) will be a key enabler to appraise and develop more resources.

Introduction
Tremendous unconventional gas resources have been estimated in China. For commercial development of such resources, fit-for-purpose technologies are required to address the technical challenges which may be specific at different project phases. In exploration and appraisal phase, the key challenges are 1) identification of the most prospective area 2) characterization of the subsurface and 3) rapid determination of the well productivity and estimated ultimate recoverable (EUR). Some of the latest technologies, successfully applied in unconventional gas in North America, can be applied to unlock the huge unconventional gas resources in China.
Advanced Cuttings Analysis Improves Reservoir Characterisation and Reduces Operating Times in Shale Gas Drilling Project
Authors: Carugo C. , Malossi A. , Balossino P. , Galimberti R. , Gioacchini L. , Rivolta F. , Previde Massara E. , Pingitore F. 
Published: March 2015

Abstract
Significant improvements in shale gas reservoir characterization have been recently obtained by means of detailed geochemical and mineralogical analysis on cuttings and cores directly at wellsite using the combined application of different technologies. These technologies include: X-ray diffractometry for mineralogy, X-ray fluorescence for rock chemical (elemental) composition, TOC analysis for Total Organic Carbon measurement and Pyrolysis for source rock characterization (Hydrogen Index, free oil content, Petroleum Potential & Maturity Index). The analyses, normally carried out in specialized laboratories, have been performed while drilling into a field unit. Dedicated procedures were also defined in order to improve the quality of the cuttings and to optimize the analyses timing to obtain near real time responses. The first field application has been carried out within an exploratory campaign for a shale gas drilling project. The rig site analyses provided in near real time complete geochemical/mineralogical log of the reservoir section. Wellsite analyses have been afterwards validated by laboratories analyses repeated on the same samples, confirming the reliability and accuracy of the rig site measurements. The Advanced Real-Time Cutting Analysis provided a strong support to the drilling operations (selection of the coring point, identification of sweet spot, etc.) resulting in significant time and cost savings in the well target phase and allowed for a reliable quick Formation Evaluation by using the organic matter and mineralogy data to calibrate the wireline logs response. The acquired data were also used to update the geochemical model utilized in the Petroleum System Model performed during the pre-drilling phase for a better understanding of the reservoir during the ongoing exploratory campaign.
Evaluating Wellbore Displacement Efficiency of Post-Slurry Overflushing and Its Effect on Injection Pressure in Waste Injection Operations
Authors: Ji Lujun , Gumarov Salamat , Shokanov Talgat , Anokhin Vyacheslav , Ronderos Julio 
Published: March 2015

Abstract
During the past decade, waste injection (WI) technology, also known as cuttings re-injection (CRI) technology, has been gradually accepted as an environmentally-friendly and cost-effective ultimate disposal method for drilling-related solids and liquid materials. In waste-injection operations, waste slurry is usually intermittently batch injected into appropriately selected subsurface formations. These slurry injections cause injection pressure and in-situ stress to gradually increase as more and more injected solid tends to accumulate in the near-wellbore fracture domain area. Moreover, solids in the leftover slurry can settle out and plug the wellbore during shut-in periods. These issues challenge injection equipments, wellbore integrity, waste domain containment and disposal capacity, and may hinder or terminate injection operations unexpectedly. Therefore, slurry must be properly overflushed from the wellbore and near-wellbore fracture area effectively and immediately. Effective execution and engineering analysis of post-slurry overflushing have become keys for successfully maintaining critical injection assets. A vigilant monitoring of surface, downhole tubing and annulus pressures makes these analyses possible in a timely and proactive manner.
In this paper, post-slurry overflushing with viscous pill and solids-free seawater is numerically modeled for analyzing efficiency of the overflushing and the effects of volume and rheology of the pill on the overflushing in a waste injection well. Moreover, the continuous pressure monitoring in two waste-injection projects in two offshore oilfields provides long-term downhole pressure data. These data were collected and analyzed for instantaneous shut-in pressure (ISIP) after each slurry injection and each post-slurry overflushing, and he effect on in-situ minimum stress and injection pressure was analyzed by comparing ISIP changes before and after overflushing. The studies on ISIP changes confirm the results of the numerical modeling in this paper.
Field studies and modeling results also show that overflushing with the appropriate rheologically-designed viscous pill/seawater sequence can decrease long-term injection pressure buildup rate, avoid wellbore/fracturing plugging and extend ultimate disposal capacity.
Study on Scour Experiment of Bottom-Supported Platform
Authors: Zhao Jing , Wang Shipeng 
Published: March 2015

Abstract
The variation of the seabed may cause the scour around the the foundation of bottom-supported platform in nearshore oilfield, when the platform is fixed on the seabed. For the severe consequences that may cause the slip of platform especially instability of the structure, which need to be paid more attentions in offshore engineering to make it work safely. So it's important and necessary to investigate the characteristic of scour and take effective measures to prevent it. In this paper, scale models are adopted in experiment to study the scour of bottom-supported platform in currents.
It can be observed clearly that the basic characteristic of scour and the evolving tendency of the foundation of the platform through the experiment of two different scales in currents. The area where could be scoured more easily is concluded by analyzing the results. Scour pit pattern and scour depth also can be got through the measurements by ultrasonic topography device. At the same time the maximum scour depth around the foundation of platform can also be inferred based on the scale models theory, which will be helpful for the more sdudy about scour prevention. And it will also have conductive effect for such engineering problem.

Introduction:
Soft soil are widely distributed in Chinese Bohai nearshore region, especially in Dagang, Liaohe and Jidong offshore oilfield, which could induce scour around submersible platform foundation in drill or explore process. Sediment scour of platform foundation could induce platform slide, even lose the stability, which threaten platform safety. Foundation scour is the most important issue of submersible platform safety operation.
Wang (1998) carried out scour experiment around submersible platform foundation in wave and current interaction. The results showed that there were scour area under platform foundation and scour holes in front and side of foundation look like U shape. Wave and current interaction increase scour probability, mainly because of the large-scale eddy erosion and current transportation. Zhong (2003) analyzed scour process and principle around platform foundation in Chengdao oilstate and researched scour origin and velocity of pile foundation, which provide reliable reasons for design and construction. Han (2006, 2007, 2009) researched the silty sand scour around artificial island and structure through series model theory and analyzed the sand scour variation under different combination of wave and current.
In order to investigate scour ability around submersible platform and take anti-scour method to protect the platform foundation, series model theory was adopted to research scour character around submersible platform. The experiment was carried out in wave tank of CNPC key laboratory of Offshore Engineering.
Use of Wireline Formation Tester Stress Measurements and Sonic Logs for Improved Geomechanical Model Construction of a Giant Depleted Gas Reservoir in Abu Dhabi Land: A Case Study
Authors: Cig Koksal , Osunluk Halil Ibrahim , Povstyanova Magdalena , Masoud Rashad , Ammari Khalid 
Published: March 2015

Abstract
Abu Dhabi land has a giant gas field consisted of layered carbonate reservoirs. The long term plan of the field has been to produce the reservoirs with the safest maximum depletion. A detailed geomechanical study was undertaken to identify changing field stresses and to understand the possible reservoir rock collapse mechanisms.
The foundation for any 3D geomechanical modeling is 1D Mechanical Earth Model that includes elastic and strength properties, overburden stress, pore pressure and magnitude and direction of horizontal stresses. The input data for 1D modeling is openhole logs (density and compressional and shear sonic logs). Image data, caliper logs, pore pressure and closure and breakdown pressure measurements are necessary to calibrate the models. To improve quality and reliability of the 1D MEMs, Abu Dhabi Company for Onshore Oil Operations (ADCO) requested lab measurements to calibrate elastic and strength rock properties and decided on pore pressure and stress measurements in one of the upcoming wells. Wireline Formation Tester (WFT) technique was selected to provide pore pressure, as well as closure pressure to calibrate magnitude of minimum horizontal stress directly and breakdown pressure to calibrate magnitude of maximum horizontal stress indirectly. Acquired compressional and shear sonic logs allowed building continues properties, pore pressure and stress profiles.

Introduction
3D geomechanical modeling was conducted for the interested reservoirs in the Bab field. The main objective of this study was to investigate possibility of formation rock collapse, particularly within severely depleted areas, and associated well collapse and completion integrity damage. This study also aimed at assessing potential geomechanics-related risks due to early depletion (cap rock integrity and fault sealing capacity).
Figure 1 shows the general workflow of this study. Firstly, 1D Mechanical Earth Models (MEMs) were constructed using available wireline logs. The measured data was used to calibrate the calculated elastic and strength rock properties, pore pressure and horizontal stress profiles. Drilling reports were analyzed to extract wellbore instability-related events to calibrate the 1D MEMs further. To better capture variation of elastic and strength properties across the reservoir, 1D MEMs were constructed for several wells. Then, a 3D MEM was built based on the static geological model and dynamic reservoir model. 1D MEMs were used to populate the mechanical properties for 3D modeling carried out for the duration of pre-production until present. The results were calibrated against the production data. The calibrated 3D model was then used to perform two-way coupled modeling for future rock behavior in the cap rock and reservoir depletion mechanism.
ComProMisE: an Innovative Method for Combining Proportion Cubes for Facies Modeling
Authors: Tawilé Eric , Ahn Sung-Bin , Schirmer Patrice 
Published: March 2015

Abstract
Compromise is a methodology that is based on an iterative solver that allows combining multiple proportion cubes given that a priori reference proportions are provided within a defined facies simulation perimeter. The novelty of the methodology is the possibility to choose the amount of imprint of a given trend while respecting quantitative proportion constraints.
It has been successfully tested on several operational studies and is now used in a routine basis whenever having multiple facies trends to manage. For each study, the proportion cubes were provided by different sources; the methodology is source independent as long as it is expressed as a proportion cube. Seismic, concept and well data are possible sources of proportion cubes.
It is tool-independent and is implemented today as workflows and scripts. It is also planned to be developed as an independent module on for increased user-friendliness.
Well Services Operations in Offshore Unmanned Platform; Challenges and Solutions
Authors: Alyafei Othman 
Published: March 2015

INTRODUCTION
Successfully performing well interventions safely, on-time, and within budget on unmanned offshore installations poses a unique set of challenges to overcome. The conditions regarding unmanned offshore installations are more restrictive than with other types of facilities, and each campaign of well services activities introduces new complexity and requirements. Three main factors affecting performance are focused on: personnel accommodation, safety systems, and weather. The limitations, lessons learned, and resulting improvements implemented from each campaign are enumerated and discussed. Additionally, some mitigating measures implemented to limit the impact from the three factors are presented.
Various strategies were employed to mitigate negative impact on campaign safety, cost, and schedule. Some challenges include how to address personnel accommodation and equipment limitations (number, size, and weight) through the use of supply vessels, DPI/DPII intervention vessels, jack-up rig, fast crew transfer, barge, and Liftboat. Another area that required numerous remedial measures was safety systems, e.g. fire water/deluge systems. Other conditions that affect performance are the reservoir's relatively shallow nature and down-hole conditions that require special rig-up. Along with scope of work challenges, weather is a major consideration when determining the intervention strategy for unmanned platforms. Determining how to limit standby time, overcome personnel and equipment limitations, and continue to work safely is the greatest challenge of all. All of these requirements formulate part of the criteria in selecting an intervention vessel/rig/Liftboat which directly impacts schedule and cost.
The major challenges over the past few years will be discussed, including their effectiveness, efficiency, and specification. Furthermore, a summary of how the challenges were overcome based on safety, uptime, and personnel accommodation is given.