bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drilling Hazard Mitigation Technology Enables Drilling Conventionally Undrillable Prospect
Authors: Hamoudi I. , Kartobi K. , Vieira P. , Saad M. A. , Torres F. , Qutob H. 
Published: October 2011

Abstract
The Nezla Field is a faulted anticline that makes conventional drilling challenging due to the presence of fractured and high pressure formations in the Triassic and Ordovician groups, representing trouble zones that jeopardize well objectives, adding costs and operational risks to the drilling process. This adverse condition was observed in the offset wells drilled with problems related to wellbore instability, lost-circulation zones and over-pressured formations leading to kick/loss well control scenarios that endangered the drilling operations and incurred significant Non-Productive Time (NPT). A Drilling Hazard Mitigation (DHM) approach was implemented to offset the risks of both deviating from the well objective and drilling plan.
The constraint to drill the planned 12-1/4" section in the well was the unpredictability of the pore/fracture pressure in the transition zone between Tags and Sandy Tags formations, representing a high level operational risk. The most optimum and reliable solution to achieve the goal of drilling this zone without loss of hole size was to set 9¬5/8" casing shallower than planned and then isolate the lower section of Tags formation (abnormally pressurized) with an Open Hole Expandable Liner. Drilling the next hole section through the low pressure formations to set the 7" casing shoe was to be resumed as per the original plan. This allowed the 6" reservoir hole section to be drilled under the Managed Pressure Drilling (MPD) mode.
The CBHP (MPD technique) was planned to drill the 6" section through the tectonically fractured Sandstone Hamra Quartzite maintaining the ECD within the drilling window limits initially defined by the predicted formation pressure and the average mud hydrostatic with which fluid losses were experienced in the offset wells. While drilling, these limits were ascertained within the range of 1.26 SG EMW - gas influx and 1.32 SG EMW - fluid losses. The CBHP drilling mode enabled to manage the ECD in between influxes and losses only adjusting the well head pressure to obtain instantaneous changes in the Bottom Hole Pressure while circulation was in progress. During the pumps-off periods, back pressure was applied on the MPD choke by pumping mud across the top of the well to compensate the Annular Friction Loss pressure. Once these limits were reached, drilling progressed with managing simultaneously small gas influxes and tolerable losses; then TD was called since the risk of simultaneous total losses and gas Influxes in the underlying Hamra fault was increasing.
This paper describes in detail the DHM technology implemented in this well and presents the successful application of such technique to enhance Nezla field exploitation. Lessons learnt and challenges encountered will be also discussed.
Novel Quantitative Method for Estimating Breaker Filter Cake Cleaning Efficiency
Authors: Fakhreldin Y. 
Published: October 2011

Abstract
Drilling operations including drilling and completion fluids are the primary source of the reservoir rock damage. Drilling fluid filtrate accumulates around the near well-bore and decreases the reservoir rocks permeability; this can reduce the oil and natural gas flow. Drilling fluid filter cake usually consists of a biopolymer such as xanthan gums, starch along with bridging materials like sized calcium carbonate particles. Polymers are used for improving the carrying capacity of the mud, and the starch along with bridging materials to establish the mud cake on the formation and minimize leak off of the drilling fluid into the formation. Cleaning mud cake is essential for all gravel pack and open hole completion wells, it is important for stimulation operations. Cleaning mud cake maximizes the production, and injection rate by minimizing the formation damage caused by the drilling fluid filtration and deposition across the reservoir rocks while drilling operations. Extensive laboratory studies were conducted to determine the extent of formation damage that occurs while drilling the pay zone section. This paper defines novel methodology involving thermal - gravimetric analysis, to quantify the internal, external filter cake clean up efficiency. The novel lab test can quantify the cleaning efficiency of any breaker; it has several advantages over the conventional methods. This paper demonstrates the benefits and the drawbacks of some breakers (including polymer specific enzymes), aiming to select the best breaker for each well condition and reduce induced damage caused by the drill-in fluid.
Novel Technique to Determine Cement Contamination
Authors: Fakhreldin Y. , Al-Sharji H. , Aghbari S. , Rashdi S. 
Published: October 2011

Abstract
In a well integrity, repair for well AB, 9 5/8″ casing perforated to fix gas breakthrough problem behind 13 3/8″ casing, right after the casings perforation, contaminated cement circulated to surface from the annulus between 9 5/8″ and 13 3/8″ casing. Oil extracted from contaminated cement sample using two solvents, hexane and dichloromethane. The extracts analyzed using gas chromatography. Hexane and dichloromethane extracts, showed that the cement has hydrocarbons in the carbon number region from C8 to C30. Hard cementitious material milled and circulated out of hole from 900 meter downward to S formation at 1440 meter. Having contaminated cement in the top part of the cement column and hard cementitious material downward to the oil reservoir at 1440 meter, then outstanding cement downward to the section TD at 2530 meter, indicates that cement above this reservoir did not hydrate at all. Cement contaminated as a result of the losses encountered right after displacing the cement, the entire cement column form S formation upward to the top of cement contaminated with S formation oil, contaminated cement settled and compacted because of the hydrostatic head above it. Compacted solids prevent further influx to take place. This case history along with the detailed demonstration including the novel lab work will present in this paper.
Underbalanced Drilling Technology for Unconventional Gas Reservoirs
Authors: Qutob Hani , Khlaifat Abdelaziz , Barakat Naiem 
Published: October 2011

Abstract
The increased demand for more sources of clean energy such as natural gas from unconventional reservoirs has forced the industry to explore the more challenging tight gas reservoirs. Tight gas reservoirs constitute a significant proportion of the world's natural gas resource and offer great potential for future reserve growth and production. However, to meet future global energy demand, access to tight gas reservoirs requires innovative and cost effective technical solutions.
Yet, tight gas reservoirs are often characterized by complex geological and petrophysical systems as well as heterogeneities at all scales. Exploring and developing tight gas accumulations are both technically and commercially challenging due to the large subsurface uncertainty and low expected ultimate recovery per well. Appraisal of deep tight gas reservoirs offers many challenges, including production rate predictions when wells are drilled overbalanced. Overbalance leads to near wellbore damage to the rock matrix and fractures. Damage to natural fractures intersecting the well can prevent their detection leading to missed productive intervals.
In addition, the operating environment is very challenging and that affects the decisions for data acquisition. The use of salt-saturated mud systems creates a contrast and uncertainty in the data. Hence, the quality of data acquired is compromised.
In the 80's hydraulic fracturing of deviated wells was the method of choice for developing tight gas reservoirs worldwide. Although sound in principle, in practice problems were experienced and caused either by poor cleanup due to fluid incompatibility, erosion of surface facilities or early water breakthrough due to fracturing into the water leg.
In the 90's horizontal drilling became common practice as new drilling technologies developed and proved to be very successful in many tight gas fields. However, conventional drilling operations introduced foreign fluids and solids into the reservoir which lead to several different formations damage mechanisms that prevented the identification of the gas production potential from these wells.
In the late 90's underbalanced drilling (UBD) was introduced, mainly to avoid the frequent drilling problems associated with total losses into these tight gas reservoirs. However, significant productivity gains were also observed and this became a key driver to apply the same UBD technology in tight gas fields.
This paper provides a technical overview of the state-of-the-art UBD technology used to develop unconventional tight gas reservoirs. Two real case histories from eastern Jordan and South West Algeria will be presented and discussed.
Full Scale Testing of Fast Swell Packer for Shallow Aquifer Applications
Authors: Pervez T. , Qamar S. Z. , Al-Abri O. S. , de Velden M. V. , Al-Houqani S. A. , Van Eijden J. 
Published: October 2011

Abstract
A full scale experimental setup was designed and commissioned for testing of swelling elastomer seals against a casing (cased hole) and formation (open hole). Actual replicate of wellbore was designed with varying inside diameters and roughness to reproduce the effect of actual formation. The Dynaset packer mounted on 7" tubular was allowed to swell against a 9-5/8" casing, while the fast swell packer mounted on 9-5/8" tubular was allowed to swell against the 12-1/4" replicated well bore. The fast swell elastomer will bridge the annulus between casing and OH to prevent total losses and to allow cement to surface. Recent drilling condition required the development and testing of fast swell packers to isolate shallow aquifers. Under actual shallow-aquifer field conditions (50°C and 0.5% salinity) 70% swelling was expected in 24 hours. However, under fresh water the swelling was achieved in more than 24 hours. It took approximately ten days for the elastomers to completely fill the irregular cavities in the replicated well bore. The test demonstrated the way the elastomers fill the asperities and was worth of observation for field engineers. The Dynaset packer at low salinity took 4 weeks to completely seal the gaps. Under high salinity it takes approximately 3 weeks for complete sealing. The measured-cum-calculated results showed that the swelled elastomers have developed an internal pressure of 50‒70 bars against the leakage. Dismantling of the test setup showed that the elastomer has swelled to brain like surface structure, which was a startling observation and needs further work. Isolation of shallow aquifers and fractured formations has been a major challenge for many years in Oman. The requirement for zonal isolation of the shallow aquifers is often compromised by the total losses. The simplicity of solution using swellables will avoid a cocktail of chemicals and will open new applications to materialize low cost wells.
A Review of Casing Drilling Advantages to Reduce Lost Circulation, Improve Wellbore Stability, Augment Wellbore Strengthening, and Mitigate Drilling-Induced Formation Damage
Authors: Karimi Moji , Petrie Scott , Moellendick Eric , Holt Calvin 
Published: October 2011

Abstract
Casing Drilling is a process in which a well is drilled and cased simultaneously. This innovative technology has been successfully practiced for the past decade. The original purpose of developing Casing Drilling was to eliminate Non Productive Time (NPT) associated with tripping drill pipe and running casing. However, during early implementation of the technology, other benefits were observed while drilling with large diameter casing. This paper reviews four of these advantages which are lost circulation reduction, wellbore strengthening, improved wellbore stability, and drilling-induced formation damage mitigation.
Casing Drilling reduces mud lost to the formation in two ways; the Plastering Effect seals off the wellbore and prevents fluid transfer between the borehole and the formation; secondly, in the worst cases where the losses can't be cured, drilling will be continued with minimized losses until the casing reaches the total depth. Reduced mud loss to the reservoir section can be directly correlated to reduced skin due to drilling induced formation damage. This leads to improved productivity of the wells drilled with casing in the reservoir section.
As the Plastering creates an impermeable mud cake on the wellbore wall the pressure containment of the borehole is augmented. This process increases the fracture gradient of the formation in near wellbore area which results in a wider operational mud weight window (Wellbore Strengthening). Wells with stability problems are among the best candidates for Casing Drilling and could be drilled trouble free. The wellbore stability benefits of Casing Drilling are due to no tripping, less mud formation exposure, gauged well, superior hydraulics and borehole cleaning, etc.
With all the mentioned benefits Casing Drilling is heralding the way to the future of the drilling industry. There have been a lot of drilling practices developed to gain every one of the discussed benefits; however, Casing Drilling offers the whole package with one unified solution.
Stacked Horizontal Drilling in Challenging Conditions
Authors: Nasrumminallah Muhammad , Baig Farooq , Hariri Nour , Bugni Michael , Akhmetov Rustam 
Published: October 2011

Abstract
In southern and central Oman, a field development campaign involves a major steam injection pattern across stacked horizontal producers for enhanced oil recovery. With a yearly goal of more than 350 wells drilled with 5 automated drilling rigs comprising injectors and stacked horizontal laterals targeting 3 different reservoirs on top of each other, efficient drilling and the reduction of time-based costs with no collision incidents have been the main concern. Because of the fast drilling pace, numerous drilling challenges were presented by the field, including losses in the top section, unconsolidated washable formations, trajectory control, shocks and vibrations, and bit walk tendencies in abrasive loose sand reservoirs causing equipment damage.
The typical horizontal producer well design planned for a 16-in. vertical and a 12½-in. section kicking off from vertical to 90° inclination, followed by an 8½-in. lateral section.
Several collaborative drilling practices were implemented in the 12½-in. buildup section to optimize drilling while building from vertical to almost 90° inclination using the steerable motor assembly delivering a dogleg severity (DLS) of 5°/100ft in unconsolidated formations. Drilling performance and hole cleaning were optimized in the 8½-in. lateral section by pumping up to 600 gal/min using a fully rotating rotary steerable point-the-bit system with PDC bit standardization to counteract the bit walk tendency at a penetration rates of 500 to 600 ft/hr. An added feature of the point-the-bit rotary steerable system is the inclination at the bit, which facilitates drilling through a 3-ft total vertical depth (TVD) tolerance window and promotes proactive decision making to avoid collision with the reservoirs above or below, with a TVD separation of up to 30 ft.
This field experience lead to a total saving of 3 drilling days in the AFE for each well. Using a point-the-bit rotary steerable system in the lateral, with added savings from eliminating openhole sidetracks, avoided a trip cost of 0.5 days. The high quality of the wellbore saved 0.5 days by avoiding a wiper trip and stuck incidents. The lateral is drilled in the narrow target using continuous inclination at the bit, which improved well outflow capabilities. Casing was run without any hang-up problems, eradicating any remedial cost.
This paper explains the methodology followed to improve the performance of drilling horizontal wells and attain 100% well delivery with a smooth borehole. It was also a step change in drilling horizontal wells using the fit-for-purpose approach (i.e., optimized trajectory, proven bit, and recommended drilling parameters derived from simulations compared to actual) to deliver wells in a cost-effective manner.
Application of Laser Technology for Oil and Gas Wells Perforation
Authors: Bakhtbidar Mahdi , Ghorbankhani Mohsen , Asfeh Mohammad Reza , Alimohammadi Mehdi , Rezaei Pegah 
Published: October 2011

Abstract
In gas and oil well completion, perforation channels must be made through the steel casing wall and cement and into the rock formation in the production zone to allow formation fluid to enter the well. This paper will present study results on using a pulsed CO2 laser to drill the perforation channels through reservoir rocks. With fiber optic cable delivery capability, a CO2 laser beam has the potential to be delivered to deep oil production zones. Effects of laser pulse parameters, beam properties, and assistant gas purging on the perforating efficiency and rock permeability will be reported. Unlike the conventional explosive charge perforation that often causes great reduction of rock permeability, laser perforation would enhance the rock permeability, therefore increasing the oil or gas production rate of the well.
Laser on time, laser relaxation time between laser bursts and sample rotary speed also affect the perforation. A laser burst is the sum of the multiple pulses over the period of laser on time. Pulsed CO2 laser with fiber optic cable delivery is a strong candidate for laser perforation application for oil and natural gas wells. Preliminary test shows that CO2 laser can perforate the rock as efficiently as the other types of high power lasers and the permeability of the rock lased by pulsed CO2 laser beam increases up to 566% compared to non-lased rocks due to clay dehydration and microfractures induced by the high temperature gradient and phase transformation volume expansion generated in the rock while lasing.
Development of a Liner Drilling System Incorporating a Retrievable Bottom Hole Assembly
Authors: Eriksen E. , Herrera D. , Moffitt M. , Jordan G. Rodriguez , Mazzaferro G 
Published: October 2011

Abstract
This paper chronicles the surface and field trials of a liner drilling system in which a liner is releasably attached to a drill string used to both convey the liner and bottom hole assembly into the well bore and apply drilling force to the bottom hole assembly. The purposes behind the development of this system are the mechanical strengthening of the wellbore provided by rotating a casing string against the open hole while circulating cuttings up the annulus during the drilling process, and to drill and case the hole the same operation, both protecting the hole as it is being drilled and allowing a passageway back to surface for the BHA if hole issues are encountered.
Both 7" × 9-5/8" and 9-5/8" × 13-3/8" liner drilling systems have been designed, built and drill tested to provide the above advantages. The purpose of this paper is to highlight the reasoning behind the development of the systems and the testing of the 9 5/8" liner drilling system. This particular liner drilling system was drill tested twice in Cameron, Texas. The first drilling test demonstrated the liner was set and reset successfully through three separate cycles over separate intervals. The second test was an attempt to reproduce the success of the first test over longer intervals deeper in the wellbore. In this test the liner hanger set only one out of three attempts, leading to the conclusion that a minor design change was required to increase the system's resistance to cuttings ingress into the interface of the hanger and setting tool.
Optimal Positioning of Occupational Therapy
Authors: Letts Lori J. 
Published: October 2011

Background. Occupation is central to occupational therapy. Although occupation is a universal experience, occupational therapists need to consider the risks and opportunities of exploring new roles and maintaining existing services. Purpose. I propose three questions to guide the optimal positioning of occupational therapy services. First, how proximal is occupation in the role? Second, how strong is the evidence to support occupational therapy in the role? Third, is the timing right for change? These questions are applied to the role of occupational therapy in primary health care. Key Issues. Occupation is proximal and the evidence is emerging to support an occupational therapy role in primary health care. Reforms make timing ideal. Implications. If we focus on the underlying principles of primary health care reform, the potential for an emerging role in primary health care is optimal. The same three questions can be used to transform and optimally position occupational therapy.
Analyse Critique D'instruments de Mesure Des AVQ en Pédiatrie: Déficits Exécutifs et Indépendance
Authors: Clavel Virginie , Bottari Carolina 
Published: October 2011

Description. Bien que l'évaluation des activités de la vie quotidienne (AVQ) par analyse de tâches soit au cœur du rôle de l'ergothérapeute œuvrant auprès d'enfants ayant un traumatisme craniocérébral (TCC), aucune étude visant l'analyse des instruments utilisés à cet effet selon leur potentiel de mettre en évidence des déficits liés aux fonctions exécutives (ex: formuler un but, planifier) n'a été recensée. But. Déterminer s'il existe des outils de mesure des AVQ qui considèrent les fonctions exécutives, validés auprès d'enfants de 10 à 15 ans ayant un TCC. Méthodologie. Quatre outils, le «Assessment of Motor and Process Skills», le «Children's Kitchen Task Assessment», la «tâche du gâteau au chocolat» et le «Profil des AVQ» ont été analysés selon des critères tels que: 1) complexité des tâches, 2) approche d'évaluation non-structurée, et 3) qualités psychométriques adéquates pour la clientèle cible. Résultats. Ces outils ne sont que partiellement conformes aux critères recherchés. Conclusion. La poursuite des études sur ces outils serait primordiale pour mieux répondre aux besoins de cette clientèle.
Brain Injury from a First Nations' Perspective: Teachings from Elders and Traditional Healers
Authors: Keightley Michelle L. , King Grace E. , Jang Shu-Hyun , White Randy J. , Colantonio Angela , Minore J. Bruce , Katt Mae V. , Cameron D. Anita , Bellavance Alice M. , Longboat-White Claudine H. 
Published: October 2011

Background. There is a lack of knowledge about how cultural ideas affect First Nations peoples' perception of rehabilitation needs and the ability to access services. Purpose. The study explored the perceptions of treating and healing brain injury from First Nations elders and traditional healers in the communities served by Wassay-Gezhig-Na-Nahn-Dah-We-Igamig (Kenora Area Health Access Centre). Methods. A participatory action approach was used, leading to a focus group with elders and traditional healers. Findings, established through a framework analysis method, were member checked prior to dissemination. Findings. Four themes arose from the data: pervasiveness of spirituality, “fixing” illness or injury versus living with wellness, working together in treating brain injury, and financial support needed for traditional healing. Implications. Funding is required for traditional healing services to provide culturally safe and responsive occupational therapy services to First Nations individuals with brain injury.