bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Application of HCl-Formic Acid System to Acid Fracture Deep Gas Wells Completed with Super Cr-13 Tubing in Saudi Arabia
Authors: Nasr-El-Din H. A. , Driweesh S. M. , Muntasheri G. A. 
Published: December 2007

AbstractThis paper describes optimization of gelled and in-situ gelled HCl/formic acid systems to stimulate deep gas wells completed with super Cr-13 tubing. High temperatures encountered in deep wells and the susceptibility of super Cr-13 to severe corrosion by concentrated HCl solutions and high chloride ion concentrations render acid stimulation a very difficult task. Therefore, extensive experimental and field studies were performed to develop a cost effective acid system to enhance the productivity of deep gas wells, while maintaining the integrity of the super Cr-13 tubing.Coreflood tests indicated that this acid system can create deep wormholes in tight reservoir cores (less than 1 md). Corrosion tests, however, indicated that protecting super Cr-13 tubulars during pumping this acid (15 wt% HCl/9 wt% formic acid) is not an easy task, especially at downhole temperatures (275°F). A very limited number of inhibitor aids were found to be effective in protecting super Cr-13 at reservoir conditions. To optimize the corrosion inhibitor package, the bottom hole temperature was measured in a few wells during acid injection.Based on lab tests and field measurements, an acid treatment was designed and applied in the field. The treated wells responded positively to the treatment. Most importantly, the integrity of the super Cr-13 was maintained. This was confirmed from chemical analysis of well flowback samples following the treatment and measurement of the tubing inside diameter before and after the treatment. The maximum Cr concentration in the flowback sample was less than 2 mg/L. Molybdenum and nickel concentrations were less than 1 mg/L. The total iron concentration was less than 200 mg/L. This value is significantly less than that noted with wells completed with low-carbon steel tubulars.
Drilling Demanding 16" Hole Section in Deep Gas Fields, Saudi Arabia: Challenges and Advances
Authors: Alkhamees Shaker , Klink Zeinoun , Isbell Matt , Ivers Chris , Scott Dan , Nawfal Nick 
Published: December 2007

Abstract
Drilling the 16" hole section in Saudi Arabia's Deep Gas fields is particularly challenging due to a complex stratigraphic section that consists of carbonates interbedded with tough bands of hard stringers in addition to an abrasive sandstone followed by dense dolomite. The operator has attempted to efficiently drill the section using both roller cone tungsten carbide insert (TCI) and polycrystalline diamond compact (PDC) technology. The roller cone TCI bits had unacceptably low rates of penetration (ROP) with short bit life that required multiple runs to finish the required section. PDC technology delivered acceptable penetration rates but inconsistent run lengths due to impact damage from vibration induced by either the bit, bottom hole assembly (BHA) or formation change. The operator evaluated several PDC designs from different manufacturers but all suffered similar problems including short bit life due to impact damage.
The operator determined to efficiently drill the section in one run and meet performance requirements would require new PDC/BHA technology. They organized a cross functional team to aggressively seek new PDC/BHA technology and state of the art motors and drilling practices to drill the interbedded rock section in one run. The team analyzed drilling operations from virtually every perspective using numerical models in addition to laboratory and field tests. The team identified PDC damage from BHA/bit whirl and vibration problems as the primary obstacle to achieving performance goals and focused their work on vibration management. The team performed BHA modeling analysis in order to develop a PDC solution that would minimize lateral and torsional vibrations. The modeling also helped determine the optimal range of operating parameters in order to meet performance requirements and eliminate BHA/bit whirl. The system solution combined high-power positive displacement motor to drive the bit harder and advances in PDC technology including improved bit stability and new cutter technology.
Due to the collaborative effort, the operator completed the demanding 16" hole section for the first time in one run using the new BHA/PDC bit combination. The application of this new technology has reduced cost/foot from $195.84 to $121.59 for a total saving of $365,681 over 4,925 ft and 226 drilling hours. The average section ROP went up from 14 ft/hr to 21.8 ft/hr, a 55% increase in ROP resulting in 38% reduction in drilling cost.
Experience with Rotary Steerable Systems in Onshore Abu Dhabi Fields
Authors: Al-Suwaidi Abdullah , Allen Frank , Taylor Randolph , Hussein Khalid , Russell Richard 
Published: December 2007

Abstract
The Abu Dhabi Company for Onshore Oil Operations (ADCO) operates a number of onshore fields in the emirate of Abu Dhabi in the United Arab Emirates. ADCO is a performance driven organization. As part of its Well Delivery Limit initiative, the company has focused on the technology enablers, and rotary steerables were seen to be one of the key technologies in delivering performance improvement.
The majority of the wells drilled in ADCO's fields include a horizontal lateral section through the reservoir. Therefore most wells require directional drilling technology and, in the past, have been drilled with conventional steerable mud motor assemblies. Due to the nature of the formations through the build and tangent sections and in order to provide directional control in the laterals, considerable orientated drilling has been required. Oriented drilling has proved to be time consuming and would often result in poor borehole quality. In order to minimize the effect of these issues and to optimize the overall drilling process, various types of rotary steerable systems have been used in a number of wells over the past year.
This paper will review the use of one of these systems. It is based on ‘point-the-bit’ and extended-gauge bit technology. The principle of the tool's design and its operational features will be discussed. In addition, selected case histories from ADCO wells will demonstrate the tool's ability to kick-off from vertical, build a smooth curve through the normally troublesome massive Nar Umhr shale sequence, and then geosteer through the horizontal section. Improvements in overall hole quality, and the benefits this brings, will be described.
A Safe Approach to Drilling Underbalanced Starts with Project Management
Authors: Williams Murray , Lewis Derrick , Bernard C. J. 
Published: December 2007

Abstract
This paper will examine the management issues, safety concerns of planning and executing a high end underbalanced drilling project. The discussion will include general safety, training, equipment, and conclusions.
Underbalanced drilling is inherently more dangerous than conventional drilling but the danger is mitigated by proficient project management, specifically, planning, training and the operational procedures followed during execution. Statistically, underbalanced drilling is still a very small percentage of worldwide drilling operations. This trend is changing as this disruptive technology is becoming more and more accepted throughout the industry. Our biggest challenge in the future will be to ensure that the past history of no major incidents or accidents attributed to Underbalanced drilling continues.
The planning that goes into an underbalanced drilling operation is more extensive than the planning of a conventionally drilled well. Some of the tools used in the planning phase of underbalanced operations include hazard identification (HAZID), hazard and operability (HAZOP), detailed operational procedures, and drawings such as equipment layout drawings (ELD), process flow diagram (PFD), valve numbering diagram (VND) and a hazardous area drawing (HAD). These processes contribute considerably to reducing the time and cost of engineering the underbalanced drilling program.
Fully Three-Dimensional Well Design Improves Margins in Critical Wells
Authors: Aasen Jan A. , Aadnøy Bernt S. 
Published: December 2007

Abstract
With the evolution of long, deep and hot wells, the design margins have become very small. This motivated the presented study and prompted the investigation for a precise well design model for burst and collapse. Although most well designs are based on one- and two-dimensional mechanics, more recent design packages include a three-dimensional version as well. It will be shown that these models are accurate only for certain conditions.
This paper presents an exact solution to the three-dimensional well design problem. Field examples demonstrate the accuracy of the new and conventional design models. The new model calculates design factors that are exact, thereby offering a tool for optimized well design. The presented theory is based on the von Mises yield criterion and the Lamé thick-walled solution for the pipe.
Challenges and Achievements of Drilling Maximum Reservoir Contact (MRC) Wells in Shaybah Field
Authors: Dossary A. S. , Mahgoub A. A. 
Published: December 2007

Abstract
Saudi Aramco's drilling strategy witnessed a change in year 2002 from drilling horizontal wells to more challenging and extended reach maximum reservoir contact (MRC) wells in Shaybah field. The objectives behind this change were to achieve the following: Improve the well productivity by providing maximum reservoir contact, reduce the unit cost of drilling ($/ft) and production ($/bbl), and to utilize the limited space more efficiently in the Sabkhah (flat areas between huge sand dunes). Different types of MRC wells were drilled, such as fork and fishbone in both open hole and cased hole to allow installing of intelligent completion packers for controlling the rate of production from each lateral. The reason for drilling different types of wells is to evaluate the impact of a well's type on the performance of the reservoir. The longest reservoir exposure ever drilled in Saudi Aramco was achieved by combining between the fork and fishbone in one well reaching up to 12.3 km (7.6 miles). Up to April 2003, eight MRC wells of different types and with 67.4 km (41.9 miles) of reservoir exposure were drilled in Shaybah field.
Real-time Decision-making for Value Creation while Drilling
Authors: Saputelli L. , Economides M. , Nikolaou M. , Kelessidis V. 
Published: December 2007

Abstract
Geological and operational uncertainties usually impair the ability of operators to achieve technical and economic goals of a drilling project. Use of real-time data integrated to the earth model has recently reduced the above uncertainties, thus improving project performance. However, the above solution has only addressed part of the overall problem of optimizing the well's economics, it cannot easily cope with the rapidly increasing amounts of data collected while drilling, and it has not been fully integrated with the control of operations yet. Therefore, we propose a multilayer and multiscale integrated strategy for decision-making while drilling and in well intervention and maximi. The proposed strategy aims to simultaneously optimize in Real-time the following four objectives (a) operational drilling performance, (b) initial well completion design, (c) well productivity and (d) value creation. By seeking to optimize an overall integrated objective rather than individual ones, the proposed strategy creates the possibility of achieving a solution that is superior to the aggregate of individually optimized solutions. In this paper we outline the strategy mentioned above and discuss recent applications that support our proposition.
Innovative Contracting Strategy Complements Technical Benefits of UBD in a Low Cost Environment
Authors: Francis P. A. , Murphy D. J. , Khan S. , Culen M. S. 
Published: December 2007

Abstract
For many years underbalanced drilling technology has been commercially exploited in North America whilst international Underbalanced Drilling (UBD) projects have been sporadic at best. Many technical papers have been written regarding these operations with the recurring theme that although the technical benefits of UB technology were seen, the overall cost was too prohibitive to justify further campaigns.
The many benefits of UBD are widely publicized; however, the highest impact that UBD can make is on the reservoir and its productivity. A recent focus in UB operations has been to quantify this benefit through productivity increase comparisons, or productivity improvement factors (PIFs) against field averages. The increased PIFs provide justification to offset the higher costs associated with the technology.
Petroleum Development Oman (PDO) has undertaken an extensive UBD campaign aimed at increasing production through the elimination of reservoir damage1. To fully evaluate the technology, the PIFs of a one year campaign were analysed and measured against a pre-defined business case to determine if UBD were commercially viable. The UBD campaign was carried out in two fields in PDO. Although this paper focuses on the Saih Rawl campaign, the issues for the two fields were very similar.
Although early production results were very promising2, the commerciality, in PDO's low cost, land operation environment, was marginal at best. Re-assessment of the approach to all aspects of the UBD operation by the Project Team, including scope of work, equipment design, equipment utilization and UBD operations resulted in improved operational efficiency and an innovative contracting strategy mutually beneficial to both Operator and Contractor. This new approach has shifted UBD from a trial to a commercially viable technology in PDO.
New PDC Technology Solves Challenging Directional Application in Saudi Arabia
Authors: Al-Hajji Ali , Klink Zeinoun , Khan Salahuddin , Isbell Matt 
Published: December 2007

Abstract
Directionally drilling the 8-V" hole section in specific areas of Saudi Arabia is particularly challenging due to a complex stratigraphic section that consists of soft, dense limestone and anhydrite with tough bands of hard stringers. Historically, roller cone bits with tungsten carbide inserts (TCI) have dominated the 8-1/2" application due to proficient steerability and ability to consistently achieve the required build rates in the soft limestone. However, multiple runs are required to finish the entire section. Conversely, Polycrystalline Diamond Compact (PDC) technology increased ROP but lacked consistency due to fluctuations in reactive torque that resulted in poor tool face control and inconsistent build-up rates relative to roller cone bits.
Saudi Aramco determined to efficiently drill the section in one run and meet performance and directional requirements would require new PDC technology. To address this challenge, Saudi Aramco and a service company organized an integrated cross-functional team composed of engineers from both companies to aggressively seek new steerable PDC technology to drill the curved section with controllable torque response and consistent directional behavior while achieving the full penetration rate advantages of PDC bits.
The team analyzed the drilling operation from virtually every perspective using numerical models, laboratory drilling tests, and field testing. The key to the PDC solution was the team process that identified the relevant drilling problems and performance requirements in order to develop the needed technology.
The team identified that poor tool face control in the soft limestone and cutter damage due to vibration problems were the primary obstacles in achieving performance goals. The solution was a PDC design with a new steerable concept that provided exceptional tool face control without sacrificing ROP in addition to improved stability and new cutter technology for prolonged bit life.
After 15 bit runs, the team reduced drilling cost by $17.55 per foot for a total savings of $857,476 over 48,871 ft and 1880.5 drilling hours. The average ROP for the section increased from 22.47 ft/hr with standard PDC bits to 26 ft/hr with the new PDC technology. The current ROP record stands at 42.02 ft/hr with the single run record footage standing at 6,229 ft.
Novel Drilling, Completion and Workover Fluids for Depleted Zones: Avoiding Losses, Formation Damage and Stuck Pipe
Authors: Reid P. , Santos H. 
Published: December 2007

Abstract
As oil and gas fields become mature, there is an increasing need to drill, complete and workover wells in depleted zones. The proximity of normally pressured zones often means that, in order to maintain wellbore stability, the depleted formations experience very high overbalance pressures – often exceeding 1000psi. As a consequence, problems such as differential sticking, deep filtrate invasion and severe lost circulation are common. In the extreme, increased costs and high levels of formation damage can make continued exploitation of fields uneconomic.
This paper describes a new fluid additive package designed to form an effective, low permeability barrier on permeable formations. The materials have been used in a wide range of water, oil and synthetic based fluids with excellent results. We present laboratory evidence and field data to show that fluid invasion is greatly reduced. This brings several important benefits: Differential sticking is greatly reducedFracture gradients are increased (increases well over 1000psi have been observed).Return permeability results, and hence well productivity indications, have been excellent.
The paper discusses the mechanism by which the additives provide superior invasion control, and the ease with which the protective barrier is removed from producing intervals.
The materials have been used onshore and offshore in most major oil and gas provinces. In addition to providing effective technical solutions, they have the environmental approvals that allow their unrestricted use in areas such as the Gulf of Mexico and the UK North Sea.
Successful Water Based Drilling Fluid Design for Optimizing Hole Cleaning and Hole Stability
Authors: Kjøsnes I. , Løklingholm G. , Saasen A. , Syrstad S. O. , Agle A. , Solvang K. -A. 
Published: December 2007

Abstract
Water based drilling fluids have been used in many North Sea drilling operations during the last decades. Traditionally, a high focus has been directed towards creating inhibitive drilling fluids with high low shear rate viscosity for optimising cuttings transport and intact cuttings on the shaker. It has, however, been recognized that there is no direct connection between cuttings quality and hole stability. In the current field it was also found that a low gel/viscosity drilling fluid is effective in transporting cuttings out of the wellbore. Following this, the content of high molecular weight polymers have been reduced and exchanged with low molecular weight polymers to enhance hole cleaning throughout the last years. Fewer cuttings are entrapped in beds down hole and are transported up to the surface. The current paper demonstrates how this low viscous/low gel strength drilling fluid contributed to improved drilling performance, where an improvement in tripping time, casing running speeds and total drilling time was observed.
In addition to changes in the viscosity a wide range in NaCl and KCl salt concentrations and mixtures have been tried and field tested. The project is currently using only a moderate concentration of KCl, which has improved hole stability. The frequency of unstable hole occurrences in a particular troublesome formation are today greatly reduced by using lower KCl salt concentration and improved well design.
The current paper explains in detail how the drilling fluid design optimizes the chemical performance and the hole cleaning performance during the drilling operation. The drilling performance for this particular field improved significantly during the last three years where the total drilling time was reduced with roughly 50% compared to earlier practice. The reasons for the improvements are mainly the changes in well design combined with the use of an effective WBM system.
Optimum Wellbore Cleanup of Drilling-fluids Enhanced by Drill-string Rotation, Reciprocation and Detergents
Authors: Nwoke Linus , Uchendu Chike , Arukhe James , Mamman Ajee 
Published: December 2007

Abstract
Drilling-fluids cleanup of casing is achieved by either turbulent flow, contact time, rotation or reciprocation across the casing waif, but combination of all gives excellent result.
The paper presents an enhanced casing welfbore cleanup methodology of combining detergents, drill-string rotation and reciprocation to clean casing and achieve a solids­ free completion fluid of less than 30NTU's (Nephelometric Turbidity Units). The method has successfully in some field applications displaced and cleaned up wells completion fluid NTU levels of less than 20 NTUs within some 2 hours of pumping time.
Cleanup was carried out in one phase as the chemical-pi/1-train is formulated to be capable of displacing the mud and cleaning the wellbore simultaneously. A one-trip consideration was given for provision of adequate spaces for the backload of mud and the containment of contaminated fluids. A one-trip phase, with rotation and reciprocation was combined with scraper-run and displacement of welfbore to creek or industrial water, thereby saving considerable rig-time. An engineered pumping design generated the required rates and turbulent flow necessary to optimally clean-up the casing.
This paper presents the successful cleanout of drilling mud in five trial wells in a Niger Delta field (referred to as Niger field).
Design, Installation, and Results from the World's Longest Deep-Water Openhole, Shunt-Tube Gravel-Pack West of Shetlands
Authors: Wilson Allan , Roy Alistair , Twynam Allan , Shirmboh Daniel Ndzi , Sinclair Garry 
Published: December 2007

Abstract
A large majority of the wells in deep-water/subsea environments are being drilled as horizontal wells to gain cost-effective accessibility to multiple sand bodies and larger reserves. Most of these wells are being completed as open holes because of the higher productivities as well as lower costs associated with such completions. Furthermore, a substantial fraction of the fields in deep-water environments requires some sort of sand control. Although standalone screen completions have been used successfully in some of these deep-water fields (relatively large sand grains and uniform particle size distributions, with little to no fines), premature sanding problems have been reported, jeopardising project economics as a result of prohibitively high cost of remediation.
In this paper, we present a significant case history on the application of the simultaneous gravel-packing and cake-cleanup technique in the Foinaven field, West of Shetland, UKCS. The well is the first gravel-pack completion in this deep-water, harsh environment, where various types of standalone screen completions have been utilised since the initial development of the field in 1994. The subject well is of 3,075-ft open hole, penetrating through two sand bodies separated by a 530-ft shale section. It is the first openhole gravel-pack completion in such an environment in the North Sea to result in 100% packing efficiency based on gauge hole calculations and a zero mechanical skin based on pressure build-up testing.
In addition to being the first horizontal well West of Shetland to be drilled with water-based mud (WBM), this was the first production well to be drilled in a new reservoir horizon of the field, discovered and brought on line in less than 10 months. Initial production from the well far exceeded expectations and the completion was delivered safely and 3 days ahead of the target time.