bluuebunny/crossref_metadata_2025_split huggingface dataset:
Friction Component of Tube Move Calculations in Unconventional Completion Design
Authors: Alexeyenko A. , Faraj O. , Adebiyi I. , Bernard Y. 
Published: January 2016

Abstract
Unconventional deep gas completions are subject to extreme hydraulic fracturing stimulation and production loads. These loads impose tough requirements on completion design. These completions must be capable of withstanding high compression, collapse, burst and tension loads.
Tube move calculation is a key part of Polished Bore Receptacle (PBR) completion design. Software simulation estimates compressional tube move due to the ballooning effect during frac operations, and the elongating tube move due to temperature expansion during production operations. With tube move estimated for all possible loads imposed on completion, selecting the right PBR length becomes possible. Current design practice is not accounting for Friction Factor (FF) in tube move calculations. This practice is acceptable for conventional gas wells completions with less tube movement where 20 ft. long PBR is adequate. When dealing with unconventional deep gas frac stimulated completions, this design approach leads to tube move requiring 30 ft. PBR or possibly longer. While the solution seems to be a simple replacement of the equipment, the impact can be huge including such issues as logistics, use of heavier completion fluid, higher slack off weight for landing upper completion and other possible, unforeseen complications.
Discussion with engineering software provider and scouting industry publications did not reveal the answer to why the use of FF is not a standard practice in software simulation of tube move. We had to find the answer ourselves, allocating drilling rig time and conducting a number of tube move measurements in actual unconventional completions. Using digital slick-line with gamma-ray (GR) and casing collar locator (CCL) logging tool the actual tube move caused by high-pressure ballooning effect was measured and the applicable friction factor was deduced. Applying friction component drastically reduces software simulated tube move and requirements in length of PBR, weight of completion fluid and slack-off weight for landing upper completion, thus simplifying the completion and reducing risks and cost.
The following paper discusses the measurement of tube move under actual well conditions and the resulting deductions on the effect of friction. Identified FF is recommended for use in optimized unconventional completion design.
Cluster Wells Applied in Wetland Environment in North Azadegan
Authors: Liu Bingshan , Wang Xi , Tu Apeng , Zhang Shunyuan , Jiang Zi , Fu Jin 
Published: January 2016

Abstract
Most area of North Azadegan oilfield is covered by wetland, especially, in the north part it is covered by reed marshland with 1.5-3m deep water. Meanwhile, there are lots of landmines left during the Iran-Iraq war. It is expensive to construct pads in this area (more than 300 million dollars for one pad). In order to protect environment, decrease dangers to construct pads and save cost on building pads, cluster well is the first choice.
In this paper, well network was optimized first based on geological requirements and environment limits. Formations upper 800m are unconsolidated, 800m-1000m mainly are shale and more stable, Gachsaran contains bout 1800m salt-gypsum in lower part with high formation pressure about 1.8g/cm3 and high pressure salt aquifer with EWD up to 2.31g/cm3. Two plans for kick off point of horizontal wells were considered, in the interval 800-1000m or below Gachsaran. Multi-well anti-collision and avoidance of obstacle were considered and the well profiles were optimized.
15 well pads for cluster wells were designed: 5 pads with 5 horizontal wells, 1 pad with 5 horizontal wells and 1 vertical well, 1 pad with 4 horizontal wells and 8 pads with 2 horizontal wells. This protects environment and saves cost expending on pads building to the maximum extent. After considering effects of KOP on dogleg and inclination and the downhole complications encountered in drilled wells comprehensively, kick off point was built in Gurpi formation about 2300m deep (below Gachsaran). Based on this, optimized the wellbore trajectory, BHA and parameters. By far, all the wells planed have been finished, there is no any collision accident, target hitting rate is 100%, drilling catching rate in reservoir is 100%, both the success rates of electric logging in horizontal interval and casing running in designed depth are 100%.
The drilling experience and expertise in north Azadegan oilfield could be used for a beneficial technical reference for drilling in such complicated environment and complicated formations.
Advancements in Well Conformance Technologies Used in a Major Field in Saudi Arabia: Case Histories
Authors: Al-Zain Ahmed , Al-Atwi Mohammed , Al-Jandal Ahmed , Al-Abdalmohsen Rami , Al-Ghafli Hashem 
Published: January 2016

Abstract
Water management practices are an integral part of effective well and reservoir management to avoid various water production problems. Water production problems are major challenges in the oil and gas industry. Many strategies have been used in the industry to control water production problems both in producers and injectors. There are many water control methods available in the industry, including mechanical and chemical methods; sometimes a combination of both methods is used.
With the advent of horizontal drilling technology, unique opportunities have been captured to enable efficient and effective water management. More complex wells of various types and shapes have been drilled and completed. The benefits of drilling these wells not only include reduction in development and operating costs because of the lower number of wells but also improvement in the reservoir performance and management of fluid movements. These complex wells are drilled for various and many objectives, which may include but are not limited to increased production, enhanced reservoir characterization, improved sweep, maximized recovery, and efficient reservoir management.
Water management practices implemented for effective water control, and to sustain oil production on two different areas in a major field are presented in this paper. One area exemplifies water management practices in a conventionally developed field, and the second area represents drilling conformance technology, utilizing smart MRC wells.
Integrated ERW Drilling Technologies for Weakly Consolidated Sandstone and Mudstone Formations
Authors: Fan Baitao , Zhang Xiaocheng , Xu Jie , Zhong Liguo , Yang Qiurong , Zhao Shaowei , Zang Ye , Chen Gang 
Published: January 2016

Abstract
There are many challenges in drilling extended reach well (ERW) for weakly consolidated sandstone and mudstone formations in Bohai Offshore Oilfield. For weak consolidated sandstone formations, it is difficult to control well trajectory, keep wellbore stable and decrease mud loss. For mudstone formations, the challenges include friction between wellbore and drilling tools, hydrating and swelling. At the same time, the measured well depth is larger than 3000 m, and the angle hold are larger than 70 degree. Additionally, the faults and the stress anomaly increase mud loss or complicate ERW drilling. Consequently, sticking of drilling tools or casing, and well collapse occur in past well drilling process.
In order to drill ERW successfully and safely in Bohai weakly consolidated sandstone and mudstone formations, integrated drilling technologies are introduced involving well trajectory design, drilling tool assembly, friction prediction and drilling parameters correction, adjustment of drilling mud, and casing floating and lubricating. The practical measures used include: (1) Different drilling technologies are employed in the deflecting section and hold angle section respectively; (2)Rotary steering-LWD tools are used in the second spud and the third spud; (3) Drilling parameters are corrected in-time according the real-time friction prediction result derived from drilling friction prediction; (4) Marine bentonite mud is used for layers over the oil formation to recover well cuttings rapidly and keep high drilling speed, and polymer enhance cation (PEC in short) drilling fluid are used while drill the oil formation to avoid sticking of drilling tools and protect formation; (5)Floating couplings and addition of lubricant are introduced in running protective casing to avoid sticking. Field testing show that above integrated ERW drilling technologies are practical for the sophisticated weakly consolidated sandstone and mudstone formations in Bohai Offshore Oilfield, and the drilling efficiency is significantly increased. The engineering design of the integrated ERW drilling technologies and field drilling cases are presented in this paper.
Acid Stimulation Studies on a Special Cement-Based Pill for Use in Weak Production Zones
Authors: Jandhyala Siva Rama , Patil Sandip , Songire Sumit , Singh Sheetal 
Published: January 2016

Abstract
The primary challenge with weak production zones is severe to total circulation loss resulting from natural fractures or low fracture pressures. A highly thixotropic engineered cement system has been used successfully in the field in several severe-to-total-loss treatment procedures involving weak nonproducing zones. This paper presents an investigation of this cement system's response to acid treatment and the possibilities of extending its use as a temporary plug to cure losses in weak production zones while helping minimize formation damage.
Tests were performed to understand the response of the highly thixotropic engineered cement system to acid treatment. These tests included acid immersion of cured cement cubes and exposure of set cement to a continuous supply of acid by exerting a differential pressure in an acid core flow apparatus. A reacted cement core forms a conductive path, resulting in a subsequent decrease in differential pressure or an increase in flow rate. Dependency on temperature and differential pressure were studied.
Experimental observations indicated that there was a formation of conductive path caused by a cement reaction when subjected to acid treatment. However, complete dissolution is a prolonged process and is unlikely to occur within the typical acid treatment times used in the field. If sufficient differential pressure is provided to allow the acid to diffuse through the entire volume of cement, a regain in permeability can be easily achieved, even with short exposure times. It has been observed that the time required to form a wormhole decreases as differential pressure increases. When acid was replaced with water, no wormhole formation or increases in the permeability of set cement occurred. This confirms that the wormhole formation is a result of the chemical reaction of cement with acid.
The study presented in this paper confirms that the engineered cement system is amenable for acid treatment. This provides opportunities to use this cement system to treat severe and total losses, as well as provide wellbore strengthening in production zones. Such an operation helps ensure that the production zone is well prepared for a successful primary cement treatment without compromising production.
A Novel System for Controlling Pore Pressure Transmission, Inhibition, Stabilization and Targeted Lubrication in Water-Sensitive Shales: Proof-of-Concept and Initial Field Results
Authors: Rea Anthony B. , Nagatani Ray , Davis Eric S. , Carlton Tim , Coragliotti Anna , Firliet Brian , Tran Sarah 
Published: January 2016

Abstract

Description of Proposed Paper
As the drilling industry has pursued more horizontal wells in water-reactive shales, the challenges from wellbore instability and high friction (e.g., stick slip, reduced Rate of Penetration [ROP], stuck pipe, severe doglegs) have led to increasing use of oil-based (OBM) and synthetic (SBM) muds. While costs associated with materials and waste-management for O/SBMs may make them more than twice as expensive as water-based muds (WBM), efforts to develop advanced WBMs that can broadly stabilize shale and lubricate have seen mixed results and limited applicability. To address these challenges, we have developed a novel methodology to control pore pressure transmission and reduce interfacial tension to rapidly and comprehensively deliver shale inhibitors within the near borehole shale pores while simultaneously targeting lubrication to high friction areas.

Application
Leveraging complex nano fluid technology as a chemical platform to convert water imbibition in shale pores into a pro-active tool dramatically reduces capillary pressures and focuses delivery of shale inhibitors within the near borehole shale pores. The combined features of reduced capillary pressure and inhibited clay platelets mitigate elevated pore pressure destabilization of the wellbore. As we have previously described, using polysaccharide-encapsulated oil targets lubrication to points of friction throughout the borehole strong enough to break the encapsulation. Laboratory and field observations indicate that these technologies can be used together to enable drilling with aqueous systems in water-reactive shale.

Results, Observations, and Conclusions
The use of these two technologies was associated with significant reduction (40 %+) in dynamic linear swell meter testing relative to incumbent aqueous shale stabilization technologies (e.g., KCl polymer) and a 76 – 91% reduction in coefficient of friction. In field testing, the technologies have been associated with keeping a wellbore stable for over 90 days (compared to an average of 12–14 days with KCl Polymer drilling fluid in the same field) and the reduction in drilling torque from 11 – 45 % in highly deviated wells.

Significance of Subject Matter
Results in the laboratory and field indicate that control of pore pressure transmission, objective inhibitor delivery and encapsulation of lubricant can be used in WBM to drill operationally and economically efficient in water-reactive shale. When employed throughout the build section of a highly deviated well the system can continue to be employed as a drill-in fluid because of its reservoir stimulation features4,6.
Optimum Mud Overbalance and ROP Limits for Managing Wellbore Stability in Horizontal Wells in a Carbonate Gas Reservoir
Authors: Khan Khaqan , Halim Abdul , Hamid Ab , Al-Anazi Hamoud A. 
Published: January 2016

Abstract
Saudi Aramco has been drilling horizontal and multilateral wells to develop gas fields. Due to production-induced decreasing reservoir pressures along with tight nature of the reservoir rock, development activities have focused more in placing wells towards the minimum horizontal stress direction and complete with multistage hydraulic fracturing aimed to improve lateral reservoir contact enabling higher production at sustained rates thereby increasing recovery with less number of wells to be drilled.
Horizontal wells drilled in the minimum horizontal stress direction are more challenging due to complex geological conditions and compressional in-situ stress conditions. The data shows that some wells were drilled without major difficulty while some other wells encountered more problems leading to stuck pipe events. A detailed study was conducted to identify the nature of these problems and ascertain major controlling factors for this variable drilling experience to make future operations safer and more efficient through recommendations based on a diagnostic analysis of the observed problems in existing wells.
Analysis of data suggests that excessive borehole breakouts and faster rate of penetration (ROP) are the key contributing factors to the observed drilling challenges. In addition, differential sticking has been found a potential risk across high porosity and/or depleted zones. As a result, optimum mud weight based on predrill geomechanics model was recommended to manage the hole stability. In addition, a safe limit of ROP as a function of hole azimuth was identified to manage efficient hole cleaning and avoid stuck pipe due to pack-off. The recommendations made based on this analysis enabled successful drilling and timely completion of several horizontal wells across the field.
Implementing the Pressurized Mud Cap Technique to Drilling through Total Loss Zones: A Way to Improve Well Control while Drilling the Reservoir in Oil Well Re-Entries
Authors: Al-Amri Khalifah , Guzman Julio C. , Al-Hashim Abdulrhman , Hassanen Ali M. , Moussa Ayoub H. 
Published: January 2016

Abstract
Drilling through total loss zones without returns at surface is a common practice for Operating Companies in the Middle East. This is known as the Mud Cap/Blind Drilling technique and it has been used for a long time in the region. The lessons learned throughout these years have produced well established procedures and "rules of thumb" for estimating mud density, volume and pumping schedule of the mud cap for different situations.
The application of this Mud Cap/Blind Drilling technique becomes more challenging when drilling through oil reservoirs with a high H2S content and combining zones with pressure regimes significantly different in the same hole section. This situation is often the case for some well designs commonly used to re-enter oil producer wells in Saudi Arabia. Under these circumstances, the main well control strategy is to maintain enough of a mud cap to prevent any migration of the hazardous gases and/or liquid hydrocarbons to the surface.
This approach often results in a conservative design of mud cap densities and volumes, which in turn generates huge expenditures in mud material and puts tremendous stress on logistics and transportation.
The Pressurized Mud Cap technique offers a safe alternative to Blind Drilling. This technique uses regular Managed Pressure Drilling (MPD) equipment to monitor the behavior of the reservoir at all times, improving the safety of the operation, by having accurate well control and realizing substantial cost savings, by optimizing the usage of drilling fluid materials and other resources associated with the mixing and pumping of the mud cap.
This paper describes the successful implementation of this technique for re-entering oil wells in an onshore field in Saudi Arabia. The paper also provides details for the equipment and procedures utilized to maintain a full column of fluid under pressure, by keeping the MPD choke fully closed while drilling without any returns at the surface. The results, when compared with the conventional Mud Cap/Blind Drilling Technique, show significant improvements in safety (well control), cost efficiency and logistics.
Optimized Drilling Approach, Yields Field Records through Very Hard Al Khalata Sandstone, in a Deep Gas Field, Oman
Authors: Roberts Tom , Djaoui Mehdi , Menezes Ruskin , Al-Bahri Salim , Vos Arjan , Hajje Mohammed 
Published: January 2016

Abstract
One of the main challenges drilling within the deep gas field "X" in Oman is the very hard and abrasive Al Khalata sandstone. The 8 3/8″ vertical section drilling performance is restricted due to abrasive wear and toughness of the polycrystalline diamond compact (PDC) cutter technology utilized, which limits both penetration and durability within the hard sandstone. Drill bit providers have typically tried heavy set drill bits to combat the early wear or damage to the cutting structure to gain performance improvements.
After an in-depth study of the application, engineers worked closely with a customer to fully understanding the true failure mechanisms through each lithology. Rock strength was analyzed along with a careful review of the current bit technology utilized. The team hypothesized that although the Al Khalata sandstone presented a cutting structure durability threat, the primary mode of PDC failure was thermal degradation and that simply trying heavier set drill bit designs to overcome this failure was not the solution.
Instead, the goal was to use a lighter set design to increase the penetration rate with improved point loading while fully engineering the PDC cutter to provide increased toughness and, more importantly, overcome the thermal degradation.
Al Khalata formation tests in Field "X" were completed after detailed laboratory testing that included cutter-rock interaction modelling to investigate the improved thermally stable PDC cutter. The initial field test utilized two 8 3/8 in. lighter set six-bladed designs equipped with the new thermally stable PDC cutter technology. Both designs successfully drilled the entire interval through the Al Khalata, Hasirah, Saih Nihyda, Ghudun, Lower Ghudun and Al Bashair formations. The result was a breakthrough in performance, setting a new interval field record including the longest 8 3/8 in. interval drilled in the Al Khalata with a PDC bit.
The results of this research led to new cutter and bit technologies which have proven that the combination of improved thermal resistance and more efficient cutter rock interaction will provide higher rate of penetration (ROP) for the section and demonstrate superior durability while drilling through the hardest stringers to complete the section. By focusing on the true failure mechanisms of the operation, the team was able to prove that improvements in cutter technology can yield breakthrough performance and in this case allow for a lighter set six-bladed design. The improved bit designs have repeatedly drilled further and faster than any previous attempts, resulting in significant cost savings for the operator.
An Integration of Drilling/Completion Technologies for Maximizing Long-Term Productivity
Authors: Lim J. C. , Cortes Pierre , Smith Lee 
Published: January 2016

Abstract
An effective approach for enhancing production and improving hydrocarbon recovery has been to integrate production engineering with drilling strategies to design well programs that optimize all aspects (hole sizes, casing sizes, well positions, etc.) for the long term exploitation of reserves.
This paper describes the use of such a multi-faceted approach in North Dakota Bakken wells and West Sak heavy oil sands in Alaska, both of which require long horizontal wellbores to be completed with multiple swell packers and/or liners. For maximum production, a smooth, well-conditioned, gauge hole is vitally important to enable the largest, most-effective and highest number of packers to be run.
Successfully getting liners to bottom so as to achieve optimum completions in these wells requires a repeatable process that is effective 100% of the time; therefore, requirements of both the drilling and production groups were combined in a strategy that integrates technologies specifically for improving the success of landing the liner on depth and helping drill a cost-effective, smooth, gauge hole.
In addition to the type of packer design / reamer/ centralizers / T&D equipment utilized, the paper describes how Torque & Drag (T&D) modeling in both the drilling and liner running intervals of these wells provided a number of strategic options for achieving a useable, quality wellbore that would facilitate running liner/packers into hole without damage. When these reaming while drilling techniques are used, excellent hole quality can be achieved without the need for dedicated clean out runs.
Demonstrating its effectiveness and applicability, this integrated approach has been employed on more than 100 wells to date, with more than 2 million feet of reamed hole alone, and more than 1,000 packers run on variety of wells, including runs in excess of 20,000 ft and laterals exceeding 10,000 ft in tri-lateral and penta-lateral wells.