bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Transient Vibrations While Drilling Using a Finite Rigid Body Approach
Authors: Pabon J.. , Wicks N.. , Chang Y.. , Dow B.. , Harmer R.. 
Published: February 2011

Abstract
Vibrations are a common contributor to premature drillstring failure. The need for a better understanding of the phenomenon has driven the implementation of real-time downhole drilling mechanics measurements. As the costs associated with poor drilling performance and equipment failures increase, so does the impact of improving the modeling of these vibrations.
The onset of downhole vibrations is complex and sensitive to a wide range of factors, some of which are difficult to quantify within a typical drilling environment. Examples of these factors are the friction factor at contact points, drillstring component imbalance and rock properties and their variability. Field experience has shown that the identification of resonant conditions using frequency domain modal analysis is of value; however, additional insight can be gained through the use of a transient vibration analysis.
This paper describes a numerical modeling tool developed to enhance understanding of the transient dynamics undergone by a drillstring during the drilling operation. A Finite Rigid Body (FRB) approach has been chosen for modeling simplicity, computational cost, and physical relevance of the computed results. This approach can be used to incorporate important transient features characteristic of a drilling operation, such as the bit-rock interaction and the interaction of the drillstring with the borehole wall, as well as the relevant dynamics introduced by drilling tool components such as mud motors and bit steering devices. A number of examples and case studies illustrate the capabilities of the modeling tool.
New Approach and Technology for CO2 Flow Monitoring and Remediation
Authors: Sweatman Ronald , Marsic Scott , McColpin Glenn 
Published: February 2011

Abstract
A novel, cost-saving approach combining rapidly-acquired CO2 flow measurements and early-alteration improves CO2 placement, leak detection, and remediation in CO2 enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects. The approach is based on field-proven technologies for monitoring CO2 flows and for controlling flows within reservoirs or remediating flows outside of reservoirs. The new low-cost monitoring technology employs reservoir flow induced micro-deformation measurements by three basic technologies—satellite-based interferometric synthetic aperture radar (InSAR), surface and downhole tiltmeters, and differential global positioning systems (GPS). These methods acquire microdeformation data in near-real-time (NRT). This data supports NRT geomechanical inversion analysis that provides 3-D reservoir flow images. Real-time temperature and pressure data from wells instrumented with sensors connected to fiberoptic cables may also be used to better characterize some CO2 flows. The new lost-cost flow control and remediation technology is derived from improvements in flowpath sealants and placement methods that can alter flows both inside and outside of reservoirs.
This monitoring technology has evolved from similar methods proven in other types of secondary and tertiary recovery projects, and more recently in CCS projects, to identify reservoir flows and pinpoint abnormal ones. An example of normal CO2 flow results is presented to show how operators can calibrate flow-prediction software models and make fast decisions to apply flow enhancing methods. These methods improve CO2 sweep efficiency, increase oil production, and better utilize the reservoirs’ CO2 storage capacity. Another example shows the early identification of an abnormal flowpath location that enables timely selection of sealing methods and materials that eliminate unwanted flows from reservoirs with negligible CO2 losses.
The CO2 flow control and remediation technology’s history of field-proven success is described along with recent developments that have improved both material and placement performance. Generic case histories of conventional vs. the proposed new approach are compared to show how the combination of rapidly-deployed, CO2 flow-alteration and monitoring technologies creates synergies that can improve the performance of CO2 EOR and CCS projects while reducing operating costs.
Unique Selection Tool Enables Scientific Approach to Matched Reamer Assemblies
Authors: Barton Steve , Weeden Ryan 
Published: February 2011

Abstract
There is a critical need to understand the interaction between a drill bit and underreaming tool in hole opening assemblies. Problems that can result from improper matching include vibration, inability to open hole, mechanical damage to string tools or to the bit, and sub-optimal drilling performance. Matching of the bit and reamer to avoid these dysfunctions is not a simple process, and certainly is not resultant from simply having a similar cutter size in both cutting structures, or from compromising the rate of penetration potential of the bit.
There are four indices that substantially describe the performance of a bit and reamer system: Aggressivity; Stability; Durability; and Steerability. A tool that is capable of calculating the four indices for a bit and reamer allows optimal solutions to be developed for an application once the importance of the rankings are defined for that application. Accurate modeling of bit and reamer solutions must investigate the torque and weight balance in a number of different lithology scenarios. This must take into account the range of compressive strengths plus the type of transition encountered. Suitability of bits for specific reamers can be assessed using a sophisticated and novel reamer matcher tool. These can be tailored, via user input, to the specific parameters of the application. This matching tool uses logic tables based on theory, modeling, and field experience to provide a consistent, logical and quantitative approach to bit selection for reamers.
Case studies are presented from deepwater applications that clearly demonstrate the value of the use of indices and reamer matching tool. In combination, these have enabled high efficiency drilling performance, reducing cost per foot to the operator.
Geological Overview of the Middle Cretaceous Mishrif Formation in Abu Dhabi
Authors: Al-Zaabi Mohammed , Taher Ahmed , Azzam Ibrahim , Witte Johan 
Published: February 2011

Abstract
An extensive play review was carried out of the Mishrif Formation in Abu Dhabi. The database existed of almost 3000 2D seismic lines and 28 3D seismic surveys, complemented by 450 wells, out of which 260 had reliable time-depth data. The study resulted in Abu Dhabi-wide depth and thickness maps and a good overview of the Shilaif basin development and Mishrif reservoir distribution.
The Mishrif Formation in Abu Dhabi comprises the progradational shelf margin facies which is a time equivalent of the corresponding Shilaif basinal facies. The Mishrif development in the UAE is strongly asymmetric.
The western Mishrif platform sediments are characterized by stacked clinoforms comprising clean, high-energy carbonates. Rudist reefs and grainstone shoals along the successive shelf edges, which form those clinoforms, generally have good reservoir properties. Similar favorable reservoir characteristics can also be found in isolated platforms and grainstone beds which are locally well developed in lagoonal settings found behind the shelf edges.
In the east, the Mishrif is generally much thinner and is characterized by more differentiated, coarsening and shoaling-upwards sequences, each grading from fine basinal wackestone to medium/coarse-grained shallow marine packstone. This indicates sedimentation on a shallowing depositional slope. This slope lithofacies is made up of dark-colored, very fine- to fine-grained, well sorted, bioclastic packstones, grading into lighter colored, medium-grained, unsorted, bioclastic packstones to grainstones. High-quality reservoir facies occur only near the prograding shelf edges and over salt domes from which build-ups may have nucleated.
Kerogen carbon isotope values and GC-MS fingerprints confirm that the Shilaif Formation is the source of the Mishrif oils. The Shilaif Formation is immature over large parts of Abu Dhabi, notably the western offshore part of the Emirate. In the deeper salt-withdrawal basins such as the West Bu Hasa and Falaha synclines the source rock is oil-mature and also in the Oman Mountain foreland basin, grading to gas mature further towards the east. In most of the mature Shilaif kitchens, oil generation commenced during Miocene times, in the southern offshore part of Dubai it may have started as early as the Early Oligocene.
The Mishrif Play prospectivity evaluation will guide future appraisal drilling and will serve as a basis for further exploration activities related to conventional and unconventional trapping styles in the Formation.
We Need to Re-think the Acquisition and Processing Parameters for Sea Bottom Seismic in the Arabic Gulf
Authors: Berteussen Karl A. , Yuefeng Sun 
Published: February 2011

Abstract
Sea Bottom Acquisition is the standard seismic method for a large part of the Arabian Gulf. Typical for the region is shallow water and large velocity contrasts, i.e. high seismic velocity just below the sea bottom. This in essence represents a waveguide and has a very dominating effect on wave propagation and penetration. To understand the challenges and the opportunities this represent, we in this study are performing full acoustic and elastic modeling and then compare the predicted results with observed 4-component (4C) seismic data. We find that although the data is very complicated the simulations to a large extent can predict the observations. We thus conclude that the modern instruments as such are giving a correct picture of the wavefield and are not a part of the problem.
The simulation demonstrates that we should expect extremely strong Scholte waves which indeed also are observed. Because of the wave trapping mechanism mentioned above, these waves keep rolling for a very long time. The way most acquisition is done they represent a considerable noise problem not only for the actual shot but also for subsequent shots. In addition these waves are under-sampled in space with the present acquisition systems. This gives rise to high noise levels that are difficult to remove because it is aliased.
One positive opportunity is that we expect strong wave mode conversion to S-waves near the surface. We thus expect to see reflected S-waves in 4C data (S-down and S-up) if we record long enough. Modeling results also shows that they will have large variations with offset and basically are destroyed the way we typically process today. These waves might have important structural and lithological information if we can extract them properly.
In sum; the acquisition challenge will be to sample much denser in space as well as shooting with much longer time difference to avoid unacceptable left over noise from previous shots. Obviously that might have large cost effects, but also large upside with regard to survey quality. In addition to noise removal one of the processing challenges will be to use model dependent processing to enhance the information from both the P- and S- waves.
Overview of the Emerging Unconventional Oil and Gas Regulatory Framework in Quebec Vis-a-vis Its Western Canadian Counterparts
Authors: Paquet P. , Bews T. , Viala E. , Pearson M. 
Published: February 2011

Abstract
Western Canada has had a thriving conventional energy industry for many decades. It encompasses the exploration, development, transformation and transportation of hydrocarbons to markets across North America.
In Quebec, until recently the oil and gas industry was limited to distribution and transportation activities. As an industry, it regulated the infrastructure needed to process hydrocarbons and the legislation had very little to do with the exploration and development of hydrocarbons.
However, with shale gas development, technological breakthroughs, and more favourable pricing conditions, Quebec has witnessed the birth of an unconventional oil and gas industry which now includes intense activity by exploration companies, developers and possibly, over the next few years, producers.
The Western Canadian regulatory framework will be reviewed and contrasted with the emerging Quebec regulatory framework to highlight the different challenges that may arise.
We will outline the legislative framework that governs the unconventional oil and gas industry in Quebec. Also, we will address the potential liability of officers and directors regarding the reclamation and abandonment of upstream facilities.
We will comment on Quebec laws regulating land use, planning and the environment which may pose specific challenges depending on whether or not local gas lines, or processing plants need to be built or implemented.
The oil and gas industry in Quebec is made subject to mining laws that are not entirely compatible with industry practices of traditional players.
The regulation of unconventional oil and gas is emerging throughout North America.
In the St-Lawrence valley in the past 5 years, there has been a thriving exploration push. This exploration could lead in the medium to longer term to the securing of defined reserves for consumption in the local market. There had been anecdotal evidence of this over the years; however, recently this possibility has become very real indeed.
Millions of dollars had been invested over the years by local entities such as Petrolia and Gastem Inc. These juniors have partnered with western Canadian or American players which have confirmed their participation and are motivated to further exploration and development of shale gas discoveries and unconventional oil plays.
Geomodeling of Giant Carbonate Oilfields with a New Multipoint Statistics Workflow
Authors: Carrillat Alexis , Sharma Sachin Kumar , Grossmann Tino 
Published: February 2011

Abstract
Geomodeling is the integrating activity when developing a reservoir description. The static and dynamic models derived during geomodeling are vital in improving recovery, understanding the various uncertainties associated with it, and, ultimately, maximizing the profitability of any oilfield.
A case study of a giant heterogeneous carbonate brownfield is presented, in which the conceptual geological model built from detailed core analysis is used to drive the facies population during the geomodeling stage. Reservoir heterogeneity mapping is captured at different scales, from rock-types identified on core and advanced log analysis to joint stochastic inversion of reservoir properties derived from seismic prestack data.
A novel geomodeling workflow is presented to merge and optimize this set of multiscale data within a geological conceptual model using several geostatistical facies modeling schemes. Two of these are based on new technologies, namely truncated Gaussian simulation with 3D trend and multipoint geostatistics, which was developed to model complex geometries. The multipoint technique allows for more flexible integration of soft and hard data compared to traditional pixel- or object-based modeling approach.
The paper compares the two approaches and shows their respective advantages. It is the first time that the two new algorithms have been implemented in a giant carbonate oilfield. The outcome of the study shows that the new multipoint geostatistics facies simulation implementation performed a smooth integration of all available data. This included log data from several hundreds of wells, high-resolution seismic properties, and the conceptual geological model.
Production Monitoring and Optimization on a Mature Field
Authors: Tournier Emmanuel , Jaffres Benoit , Geoge Bina , Sabally Lamin 
Published: February 2011

Abstract
Mature fields require an efficient production monitoring in order to optimize the production. The use of several recovery techniques (water and gas injection) and lift methods are generating new challenges due to reservoir changes (high water cut and gas breakthrough). In order to relieve such challenges, with producers over 90% water cut and a great diversity of producing configurations: natural flowing, gas lifted and ESP driven wells, some tools based on commercial software have been implemented.
The global field potential and shortfalls are monitored on a daily basis, using the status of wells, the surface facilities constraints and well & field events.
The potential of each well is measured with two conventional production test separators and one multi-phase flow meter which allow monitoring closely the oil, water and gas flow rates in real time. The activity of both separators and multiphase flow meter is monitored every day in order to maximize their activity and detect anomalies which could impair the test quality and frequency. Dedicated tools have been developed and tuned for operated field & well configurations in order to follow-up in real time the well and gas-lift stability. The different customized tools implemented in this field allow reacting more efficiently in order to minimize the loss of production.
A full production network model, including the global outflow system based on well and surface parameters has been built. This model allows to compare production figures with predicted ones and therefore to identify more precisely the origin of production losses and the possible remedial solutions. Moreover, optimizations are performed on gas-lift injection target rates as well as on ESP’s frequencies on a daily basis.
Several critical scenarios of surface equipments failures are constantly tested and updated in order to provide to offshore team relevant solutions to lower impact on field production. The different scenarios simulated are taking into account production constraints: gas availability, water production & flaring limitation, shut-downs of critical surface equipments such as gas compressors.
A New Method of Average Pressure Estimation for a Horizontal Well in a Pattern Water Flooding System
Authors: Nomura M. , Al Dahmani Abdulla Rashed , Al Jawhari Mohamed Omar 
Published: February 2011

Abstract
Periodical PBU/PFO surveys have been conducted for monitoring horizontal wells and reservoir pressure maintenance in five-spot water flooding patterns in a giant carbonate reservoir located offshore Abu Dhabi. Although, in the literature, several methods have been proposed to estimate average pressure over a drainage area, none of such methods is applicable to the situation above where a flood pattern is confined with constant pressure boundaries. In this study, we propose a new method of average pressure estimation for a horizontal well in a drainage area associated with constant pressure boundaries. This new method was developed by creating a type curve representing a pressure correction against P* or an extended pressure as if an infinite reservoir existed. Although this method may look similar to the classical MBH theory, we can substantially differentiate the new method from the MBH method since the new method can handle both a horizontal well and a constant pressure boundary while the MBH method assumes a vertical well and a no-flow boundary alone. New pressure correction type curves were generated through intensive numerical simulations modeling a horizontal well in a square and rectangular drainage with a constant pressure boundary condition. The shape factors under a steady state condition were defined and calculated to characterize and differentiate the shape of individual type curves.
Maximizing Value of a Giant Offshore Asset through Proper Production Planning, Optimization and Capacity Management
Authors: Karim Amin Alaa Abdel , Al Zaabi Ahmed , Elamin Mohamed , Al Kiyoumi Ahmed , Tariq Syed M. 
Published: February 2011

Abstract
The fundamental objective of operators of oil and gas fields is to maximize hydrocarbon production from their assets safely, economically and without jeopardizing the ultimate recovery from the producing reservoir. It is a challenge to achieve this objective for a large, complex and dynamic system like the subject offshore field.
The production planning process is a key task within reservoir and production management to maximize production. Recognizing the importance of proper production planning and optimization, a dedicated team was formed in ZADCO in 2008 to enhance the work flow/process for production planning. In this paper, we present how the team modified the existing work flows/processes using a new string-by-string planning, optimization and monitoring tool to transform the existing reactive production planning procedures to a proactive and dynamic production planning process. The focus has been on integration of different components of the production optimization process and enhancing communication among all stakeholders. The new system allows for continuous monitoring of the planned vs. actual and facilitates quick adjustment of the forward plan to achieve the planned targets. The paper outlines how the integration of work processes between various disciplines is achieved so that decisions could be made with common view of the status and challenges ahead. New software tools, developed in house in ZADCO, help achieve this work flow in an efficient manner.
The new production planning system has been implemented in ZADCO since March, 2009. The results show better compliance with reservoir/shareholders guidelines, reduced response time, improved "what-if" abilities and faster decisionmaking to deal with complex situations. Although the system is in initial stages of implementation, it has already resulted in an improvement in the operational efficiency of ~3%, which translates into thousands of STBD per day of additional production availability for the field.
Independent Simultaneous Sources Seismic Acquisition in Libya - Full Scale Implementation and New Developments
Authors: Foster Mark , Howe Dave , Allen Tony , Buddery Dave , Jack Ian , Choi Albert 
Published: February 2011

Abstract
Howe (2008) has reported on a proof of concept of a new land seismic acquisition technique called Independent Simultaneous Sources. This paper describes a full scale implementation of this ISSTM method in Libya, where it is being used to acquire a very large exploration land seismic 3D survey in excess of 13,000 sq.kms
Recent developments in seismic recording systems allow for a recording spread to be continually active, which we refer to as continuous recording, although it may be more accurately described as recording of a set of contiguous records. This removes the necessity for real time synchronization of sources and recording systems. As long as the continuously recorded data and the source initiation can both be linked to the same time standard, (e.g. GPS time) the traditional shot records can be combed from the continuous dataset at any later stage. We have used the benefit of continuous recording to operate a large number of sources simultaneously on a large recording spread thereby greatly improving the productivity of land acquisition.
In this method all vibrators work independently without any attempt to synchronize their activity, and the underlying principle is that all interference between sources can be treated as ‘noise’. The noise is randomized as much as possible, and a standard suite of noise removal tools can be used during processing.
In our simple and robust approach, there is no apparent limit to the number of sources that can be operated simultaneously, there is no waiting time for any vibrator and very little central control or communication is required. It is very well suited for work in many environments including difficult terrain, where vibrator manoeuvering is slow, or where radio communication is challenged.
We demonstrate that this technique can deliver very high fold data at high efficiencies, such that it enables land 3D to be acquired for exploration purposes at costs comparable to marine exploration surveys.
We also report the initial results from field trials of a cable-less node recording system which, when combined with the efficiency of ISS, has the potential to change the way land seismic crews are configured and operated.