bluuebunny/crossref_metadata_2025 huggingface dataset:
Milling Casing Exit Windows from a Hydraulic Workover Unit at Small Footprint Platform
Authors: Hoe Cham Soon , Hogg Cliff , Wibisono Rahmat , Barker Ron , Stutts Randy
Published: August 2014

When first discovered, the gas field located in New Zealand was one of the largest gas fields in the world. After more than 30 years of production however, the reserves have declined drastically. To manage the decline, infill drilling campaigns have recently been initiated to access previously bypassed gas reservoirs in the field.

A development campaign to boost the field recovery factor was kicked off with the objective of boosting recoverable reserves and extending the life of the field by drilling four sidetracks from existing depleted wells. A lightweight, compact and modular hydraulic workover unit (HWU) was installed on the previously unmanned, small footprint production platform with a small crew size of 32 people. While slimhole drilling and completion with a HWU had proven cost effective and a successful concept during previous workover campaigns, sidetracking from larger casing sizes at 2000-2400 metres depth with a HWU, including one dual casing exit design in this campaign, was the first of its kind for the operator.

The four sidetracks were completed and the operation was a technical success, in large part due to the pre-job planning, project management and identification of unique challenges to this particular project.

This paper will discuss the operational challenges encountered by the HWU including BHA handling and tripping in of the whipstock assembly when working with only a 12-foot jack stroke and minimal deck space. Additionally, the minimal rig capabilities of the HWU created challenges with regards to optimum whipstock and milling configurations/operations resulting from limitations on rotary torque capacity, rotary speed, pumping capacity and drill string racking capability, all of which were resolved by creative applications of the simple, robust yet versatile design of the casing exit technology.
Cementing Challenges and Slurry Selection for the Critical HP/HT Wells in the State of Kuwait
Authors: Al-Foudari Saud Jumah , Al-Muhailan Mohannad , Debroy Amalendu , Modak Tarasankar
Published: August 2014

This paper is based on continuous cement job improvements carried out for deep HPHT wells over the last ten years by KOC and their cementing service providers. The particular challenges in these complex wells compelled us to place primary attention on well construction aspects while also considering long term well production. Because of narrow annuli, dense saline water in formation situation cannot be managed with other tools like ECP/Swellables etc. Our cement slurry is designed to be pumped in place without sacrificing its intrinsic qualities. It responds in a predictable manner and confirms by testing and simulation under relevant conditions including multiple producing layers with pressure variations.

KOC cementations described cover the deep wells in a depth range of 16,000 to 19,000 ft., with possible strength retrogression because of temperatures, narrow difference of pore and frac pressure, mud weight ranges of 19.5 to 20.0 ppg, three liner systems, and a seven string casing policy. Encountered difficulties have included inability to displace from the string, wet shoe track, hanger top leakage and poor quality cement sheath in the annulus.

Different combination of spacers and slurry weight have been tried. Many HPHT cement additives were trialed and eliminated and new ones introduced in order to achieve success. Extensive laboratory testing and software simulation was done to finalize slurry designs. Slurries were selected to meet both drilling and production requirements. This approach will be detailed in the paper including examples. This paper will explain the criteria of selecting the most suitable slurries that comply with best practices for successful HPHT cementing. It will detail slurry selection methods for a number of practical cases including: formation fluid influences, prevention of gas migration, slurry property changes with hydrostatic pressure variations, and influence of high percentage of non-cement materials in the slurry.

The subject matter of this paper is very important in deep HPHT wells slurry selection and placement. This case history is developed referencing the wells drilled in Kuwait, but the concepts will have significant relevance for application to similar wells in other regions.
Hybrid Drill Bit Combining Fixed-Cutter and Roller-Cone Elements Exceeds Expectations in Challenging Application in Tarim Basin, China
Authors: Xu Zhixiong , Jia Yinglin , Zhou Jian , Wu Chao , Liu Yun
Published: August 2014

Hard and interbedded formations with conglomerates proved a significant challenge to operator, contractor and Service Company in terms of drilling performance, equipment and tool failure. Fixed cutter bits (polycrystalline diamond compact-PDC) experience severe damage resulting in short distance drilled and trips. Roller cone bit normally drill much slower than a PDC bit. The use of conventional PDC and roller cone bits leads multiple runs and trips, resulting in significant higher cost and rig time. By using the hybrid drill bit which combines fixed-cutter and roller-cone elements, higher penetration rate (ROP) is sustained, drilling distance is increased and vibrations are reduced compared to using only PDC or roller cone bits.

Drilling in Tarim Basin, Northwest China has a similar challenge which is to drill the entire conglomeratic interval with improved ROP and reduced vibration while reducing tools/bit related trips.

This paper describes the detail of the first fixed-cutter and roller-cone hybrid bit trial in the Tarim Basin, Northwest China. Result shows over 150% ROP improvement over the best offset record. Five PDC bits and one roller cone bit were replaced saving 16 rig days. The bit drilled smoothly without severe vibration (torque related) and equipment/tools failure.
Mandatory Foundation Assignment - A Fast Track Approach to Fill Competency Gaps
Authors: Al-Daihani Eisa Hadi , Nandi Arun Kumar , Matar Maqhim Bander , Valdivieso Juan Pablo , Usmani Shereen
Published: August 2014

The desire towards international standards of performance and increasing nationalization of technical manpower has caused a major shift in how the oil and gas industry trains and develops its workforce. Like Kuwait Oil Company (KOC), many companies are facing problem due to bimodal age distribution of their technical manpower i.e. a sizeable group of experienced personnel nearing retirement and a large pool of younger, new or recent hires, but a shortage of fully qualified, mid-level technical workforce.

Present paper deals with Mandatory Foundation Assignment (MFA) which is a unique out of box idea of recent times to train fresh graduates in a shortest time period. An excellent planning like identification of real ongoing projects, rotations, site visits, periodical assessments including assessments in the final presentations and involvement of Training Coordinators, Mentors and Coaches are some of the factors which made this a grand success in KOC. The uniqueness of the MFA is to expose fresh graduates to real ongoing projects under the guidance of a Coach with added E learning courses to understand the overall objective of a Geoscientist or Engineers working in Exploration or Field Development with no extra cost to company.

Emphasis has been given to the sub-surface technical manpower, the processes of MFA and different elements involved in the success of the program. The MFA is a part of roadmap which has established a framework of fresh graduate's development system in a rotational format of 4 months each. This is a practical approach to train new hires in real work environments at an accelerated pace whereby they contribute to completing on-going projects. The MFA provides a solid work foundation and necessary knowledge and skills to become independent operational employees able to carry out basic routine tasks with minimum guidance after completion of the program.

The success of the program is evident in KOC as seven cycles of MFA has been completed with around 70 recent hires have become not only operational but also developed confidence to deliver their work and new findings in technical presentations in International Conferences.
Meeting Drilling Fluid Challenges in Gulf of Thailand Ultra-High Temperature Exploration Wells
Authors: Charnvit Kerati , Huadi Fransiskus , Promkhote Chakkrawut , Aldea Catalin , Power David , Kongpat Nitipong , Segret Gilles
Published: August 2014

The definition of ultra-high temperature (uHT) conditions varies depending on regional average well temperatures. In the Gulf of Thailand (GOT), uHT is defined as a well with a bottom-hole static temperature (BHST) exceeding 450°F (230°C). Recently, a national oil company began requiring a drilling fluid stable up to 520°F (270°C) for exploration wells, especially when the actual BHST is uncertain. This paper describes the development and stability of a drilling fluid approved by the operator for these extreme well conditions.

Typical exploration wells in the Gulf of Thailand require 6 1/8–in. hole for their primary target interval. Beside the extreme BHST, the slim and deviated well geometry (up to 60° inclination), and the potential for highly acidic gas (CO2 and H2S) contamination, presented extreme conditions for prolonged successful open-hole wireline logging operations (up to 4 days), which was the most critical objective for the exploration wells. Successful open-hole wireline logging is also imperative for perforating and further production from the typical thin layers of sandstone reservoir.

New additives provide a thermally stable non-aqueous fluid (NAF) enabled logging and evaluation under the severe down-hole conditions. The novel emulsifier and fluid-loss-control agents were introduced after undertaking an extensive laboratory-testing program. Apart from the newly introduced products, fluid engineering and improved field practices also played an important role in the success of these exploration wells.

The successful achievement with this novel NAF facilitated the planning of additional uHT exploration wells for the near future. In addition to the successful logging program, the novel NAF minimized non-productive time and mets the objectives set for the exploration wells comparing to the conventyiaonl NAF.
Potentiality for Pre-Well Planning in Development Field - The Next Step to Reducing Time and Enhancing Well Planning by Collaboration Drilling's and Geoscience's Workflow - Case Study: Development Field in Gulf of Thailand
Authors: Boonsri K. , Natepracha J.
Published: August 2014

The majority of the fields in the Gulf of Thailand can be classified as small lateral gas pockets in which the combinations of complex structural and stratigraphic traps form the primary geological closure. Commingled production from multilayer reservoirs and a strategic development plan should enable a successful, viable project. These objectives will pose challenges to drilling operations because they require major expenditures. Because of limited resources, such as recoverable reserves, budget, manpower, and technology availability, pre-well planning is vital. Generally, the well trajectory design is directly controlled by many factors. The most influential of these factors include prospects, infrastructure, tectonic structure, and well proximity. One of the challenges in the past has been the well trajectory, which was determined by both geosciences and drilling engineers. For example, numerous iterations and discussions between both parties result in the identification of subsurface and engineering constraints, including drilling parameters, hazards, seismic anomalies, faults, and well spacing. This paper focuses on the integration of those concerns by using integrated well planning software to improve workflow processes and manpower and, ultimately, to optimize asset value. The process will begin with data gathering, optimizing the platform location, performing target selection/target picking, determining the well trajectories, and creating the drilling plan. As a result, drilling concerns will be mitigated at the beginning of the well planning stage through the collaboration of the team members. The objective of this work is to enable the well to penetrate the planned targets in a controlled manner and with a safe operation, thereby minimizing drilling costs.
Success Story: Improving Zonal Isolation with Engineering Microcement to Enchance Oil Production in Tiung Biru Field
Authors: Prasetyo F. B. , Inayah F. , Widyarsa I. , Pasteris M. , Rizal Y. K. , Setiariadi M. H. , Munadi Munadi , Heriyanto Heriyanto
Published: August 2014

Tiung Biru field is a promising development field in East Java, It yielded many discoveries including the Kujung Reservoir containing both gas and oil zones. The operator is only focusing on producing oil zones thus requiring a good annular zonal isolation quality to be able to produce the oil zones without producing the gas zones. Once well construction was finished the cement bond quality behind casing appeared to be mediocre which was compromising the operator production objectives for a number of oil producing zones.

Two producing wells in Tiung Biru (TBR) field which produced from Kujung Reservoir were inefficient because of a significant increase of gas production cross flow. A CBL showing high amplitude across the production zone is a strong indication there is communication between a gass bearing zone adjacent to the oil producing interval. Therefore, squeeze cementing was proposed. The success criterion for the squeeze job is the reduction of the GOR (gas oil ratio) by isolating the gas zone from the oil interval close by. The first squeeze cementing attempt was performed with a conventional cement slurry; post job logs showing mediocre cement quality log result and the squeeze was unable to isolate the cross flow. Conventional cement will hydrate and bridge off before it can achieve objective.

This paper explains a solution for improving zonal isolation with an engineered and optimized microcement slurry with low fluid loss control, thin filter cake, low rheology resulting in a better stability and performance for the squeeze application. This paper also presents slurry design, execution procedure, pre and post job evaluation.

On the execution, slurry can go through the narrow gap behind the casing and improve zonal isolation with evidence of perfect post cement log quality. The slurry penetrated the narrow gaps without dehydrating, and showing good mechanical properties with short setting times (Moulin et al, 1997) which is of prime importance to seal off gas zone and meet isolation objectives. Production test after squeeze also shows that the GOR had reduced drastically.
Resistance to Abrasive Wear and Metallurgical Property Assessment of Nine Casing-Friendly Hard-Banding Alloy Chemistries: Abrasion Resistance Assessment Using ASTM G65 Methodology (Standard Test Method for Measuring Abrasion with Dry Sand/Rubber Wheel Apparatus)
Authors: Haberer Joseph F. , Gates Jeff , Fifield Robin
Published: August 2014

Modern drilling areas often involve extremely abrasive formations in conjunction with drilling practices that can include high build rates - short radius well bore sections, long extended horizontal sections, laterals, HDLS, spiraling - tortuous wellbores with high torque and drag. Any one of these conditions taken sindividually can contribute to the rapid wear and downgrading of a drill string and down-hole tools. More often though, a combination of the above conditions is the reality, all contributing to accelerated rates of wear oln downhole tubulars and tools. Hardbanding of drill pipe tool joints, BHA, and tools has long been accepted and used in the drilling industry as a means to provide a replaceable wear component to combat the down-hole abrasive wear that can rapidly render pipe and tools unfit for service, increase the risk of failure, and significantly raise drilling costs. The main issues for the end users of any of these hardfacing alloys are how well does each alloy family type actually protect drill string and down-hole components from abrasive drilling conditions, extend the life of the pipe and tools, as well as reduce the number of times a hardfacing material needs to be reapplied during the life of the component. The paper presents the results of metallurgical examinations and abrasion resistance testing performed on various commonly used oilfield casing-friendly hardfacing alloy materials / chemistries. The total test regime included alloy chemistry, hardness, microstructure examination and measured durability / relative life of each hardfacing. Comparative abrasion resistance testing of the alloys was accomplished using ASTM Standard Test Method for Measuring Abrasion with Dry Sand/Rubber Wheel Apparatus (ASTM G-65). All testing was conducted and final comparative results are reported using a blind - numbered designation protocol assigned to each alloy type and each separate test.
A Quick Analysis of Pore Pressure Change and Formation Strain of Overburden Formation during Production and Injection
Authors: Morita Nobuo , Fuh Giin-Fa
Published: August 2014

When reservoir compaction occurs during production, the overburden formation deformation results in ocean floor subsidence and lateral movement. When a long term water or CO2 injection operation is performed, the overburden formation becomes unstable due to the reservoir expansion. These field operations induce formation strain and pore pressure change in all overburden formations. Predicting the magnitude of formation strain and pore pressure change is important for analysis of borehole stability, casing stability and overburden formation stability.

Two methods are developed in this paper. One is an analytical method assuming no mechanical property contrast between overburden and reservoir formations. The other is a set of figures created by a numerical model for predicting formation strains and pore pressure change during compaction and expansion with mechanical property contrast between overburden and reservoir formations. The parameter analyses give the following results:

Formation strain becomes significantly large if the Young's modulus of overburden formation becomes small. The casing design must be conducted including the formation strain of cap rock. If the shear modulus between overburden and reservoir formations is similar, the pore pressure increases at the overburden formations. However, if the difference of the shear modulus is large, the pore pressure decreases in the upper and lower cap rock with reservoir compaction. This new finding may change our common sense of pore pressure change of shale section around a reservoir.

This paper provides a set of equations and figures to quickly predict the pore pressure change and formation strain focusing on overburden formation where casing and formation stability problems are induced during production and injection operations. If the quick analysis indicates that the overburden strain and pore pressure change significantly affect the field operations, comprehensive analysis must be conducted with a geomechanical finite element model using a super computer.
Optimization of Drilling Method and Well Design to Drill Deep Well with Limited Equipment Capacity
Authors: Intrachai Kawin , Arkayamas Panit
Published: August 2014

One of PTTEP's joint operating company in MTJDA within the Gulf of Thailand has had the obligation to supply gas at its maximum capacity at all times and exploring the deeper territories is the only approach to acquire new reserves within the confined development area. This results in some complications both in drilling engineering and operation, which generally requires larger rig with higher day rate and more expensive technologies.

After the operator successfully drilled and completed Muda-9, one of the deepest exploratory wells in term of vertical depth in Muda field, in 2011 with 7,500 psi rig, the operator intended to drill MDE-13, a development well of the same vertical depth, in reference to Muda-9 with a smaller rig of 5,000 psi capacity, having a long term contract with the operator. MDE-13 having a planned depth of 3,065 mTVD/4,207 mMD became the first 5 casing strings for the operator's development well with the highest pressure of approximately 1.85 SG or 8,200 psi at TD. To prepare for drilling MDE-13, there were several concerns during the well design stage relating to rig pump capacity, narrow margin between pore and fracture pressure, an extremely small hydraulic fracturing target, higher temperature, and strength of tubing cement. With the comprehensive well design and the use of proper equipment, however, the operator lessened the associated risks to the acceptable level and the actual drilling operation went well without any major down time. In fact, the normalized time taken to drill MDE-13 is approximately the same as the time taken to drill Muda-9 despite the utilization of smaller rig and much stringent directional control, resulting in the estimate cost saving of the rig day rate of approximately 1 MMUSD.

The main objective of this paper is to present how the operator designed and drilled one of its most difficult wells successfully deep into the proximity of higher pressure and temperature environment with a relatively small rig and equipment limitation while maintaining the acceptable safety standards. The well design and practices of this development well are intended primarily for wells drilled in Gulf of Thailand area.
Offshore Exploration Program Benefits From Rolling PDC Cutter Technology, Timor Sea Australia
Authors: Giumelli Martin , O'Shea Paul , Maliardi Alberto , Sosnowski Paul , Shepherd Aaron , Sadawarte Sagar Sudhakar , Scordella Maurizio
Published: August 2014

Exploration offshore Australia requires the operator to drill an 8½” vertical borehole through the difficult Plover sandstone. The highly abrasive formation, with unconfined compressive strength between 15–30kpsi, has been problematic causing extremely short PDC bit runs and low rates of penetration (ROP). Erratic torque response was causing a reduction in bottom hole assembly (BHA) performance and system reliability. The operator required a PDC bit solution to increase run lengths and ROP.

To solve the problems, a new system was devised that enables a PDC shearing element to fully rotate while drilling to increase cutting efficiency/bit durability while reducing frictional heat. To strategically position the rolling cutters (RC) to obtain maximum benefit, a forensic analysis was performed on PDCs used in offsets. After investigation, engineers identified accelerated wear flats in the shoulder area and a new PDC design (RC813) was implemented by positioning two 13mm rolling cutters in the shoulder area on each of the eight-blades. The target objectives would be to drill the 8½” hole section through the Plover with one PDC bit and improve ROP.

The first well required one conventional PDC and one RC813 to drill through the Plover to TD. The standard PDC (10blades/16mm) drilled 90m (3739–3829m) at an average ROP of 5.4m/hr. The bit was pulled for low ROP and graded 8–3-CR-C-X-IN-BT-PR. The rolling cutter equipped RC813 drilled 126m (3829–3955m) at a ROP of 4.3m/hr. The RC813 was pulled in good condition and dull graded 1-2-CT-S-X-IN-PN-TD.

Parameter/bit adjustments in the second well enabled an RC813 to drill the entire Plover interval (3283m–3425m) in one run at an ROP of 9.26m/hr. The rolling cutter PDC bit run was 319% faster than a direct offset that required four standard bits to TD the section at an average ROP of 3.1m/hr. The RC813 torque response was smooth compared to erratic torque response of standard PDC in Plover. The increased meterage and ROP saved the operator over $1million USD.
Experimental Study of Gas Migration Prevention Through Cement Slurry Using Hydroxypropylmethylcellulose
Authors: Abbas Ghulam , Irawan Sonny , Kumar S. , Kalwar Shuaib A.
Published: August 2014

Gas migration during primary cementing is considered as an oil and gas industrial problem for many years. Currently, the gas migration problem is mitigated using modified cellulose based polymer (synthesized with carbonates) in cement slurry at high temperature. However, there is no widely accepted single polymer that can prevent gas migration without synthesization for high temperature cementing application.

This study presents an experimental investigation for prevention of gas migration through cement column during transition state of cement slurry. A natural polymer Hydroxypropylmethylcellulose (HPMC) is used for the first time ever as a cement additive to achieve desire prevention, which is stable at high temperature. The gas migration through cement slurry was determined using Cement Hydration Analyzer (CHA). HPMC was found to develop an impermeable barrier for prevention of gas migration. The experimental results showed that HPMC based cement slurry was gas tight as pore pressure remains low as 16 psi with constant gas injection of 150 psi for continues 08 hours. Further, API properties of cement slurries were determined using 0.20 to 0.50 gallon per sack of HPMC. The test results showed 04 to 06 hours thickening time, less than 30 minutes transition time, low fluid loss and high compressive strength at 190 °F. It is concluded that HPMC prevents the gas migration and significantly improves the API properties of cement slurry. In field applications, the presented HPMC polymer can simplify the design of cement slurry and prevent gas migration through cement slurry at high temperature.
Fatigue Strength Evaluation of Drill Pipe for Challenging Scientific Drilling Operations
Authors: Inoue Tomoya , Sakura Koji , Fukui Toshihiko , Kyo Masanori
Published: August 2014

The scientific drilling vessel Chikyu is performing challenging deep and harsh drilling activities. Generally, the fatigue strength of a drill pipe is a critical factor governing the performance of challenging deep drillings. Authors therefore established the evaluation method of the cumulative fatigue of the drill pipe and the drilling programs including the drill string configurations are planned based on the evaluation. The bending stress distribution of a drill pipe, which refers to the maximum locus of the bending stress during the drilling operation, was analyzed considering interference of the drill string with the structure, riser or drilling equipment. The occurrence probability of ship inclination due to ship motions and ocean current, the occurrence probability of the bending stresses, and the axial dynamic stress and its occurrence probability were analyzed. Consequently, the cumulative damage ratio and the possible duration of operation were obtained.

This study focused on the strength evaluation of the drill pipe for challenging scientific drilling operation at Nankai Trough that is a harsh environment because of the strong ocean current. From the results, we confirmed how severe the challenging scientific drillings are.
Optimizing Well Design in Saudi Arabia: Successful Application of Managed Pressure Drilling Enables Drilling Across Multiple Pressure Zones and Running Liner Using Constant Bottom-Hole Pressure Technique
Authors: Pinero Zambrano N. O. , Al-Ageel I. M. , Muqeem M. A. , Al-Mutawa A. S. , Mazouz C. M. , Hadj-Moussa A. , Zeb A. , Al-Ghamdi F.
Published: August 2014

Khurais field has seen, on an average, a 35% increase in reservoir pressure during the past three years due to water injection for production maintenance. A workover campaign started two years ago to reenter and workover some of the power water injection (PWI) wells. The campaign saw a dramatic increase in non-productive time (NPT) due to differential sticking and loss of circulation as well as difficulty in working over these wells conventionally.

Subsequently, Saudi Aramco started a campaign in late 2012 to workover these wells utilizing managed pressure drilling (MPD). MPD has enabled personnel to workover these wells at a 20% reduced mud weight, preventing stuck pipe and fishing related NPT.

This paper summarizes Saudi Aramco's experience gained during the working over of a well where drilling two formations together enabled the target hole size to be maintained as well as eliminating running the expandable liner for pressure isolation between these two zones. It further highlights the operational complexity and the challenges faced during the implementation of this technology while drilling the two formations with varying pore pressures. It also elaborates on the interdisciplinary team that was instrumental behind the safe and successful implementation of managed pressure drilling.

The paper also elaborates on the lessons learned and how they were implemented continuously with regard to health, safety and environment (HSE) during the workover operations. The long-term goal was to evaluate whether the application of MPD can be extended to other asset teams/areas effectively to reap its potential benefit.
Using High-Strength Dissolvable Metals to Increase Flow Assurance in High-Temperature and High-Pressure Environments
Authors: Carrejo N. , Kellogg B. R. , Gaudette S. L. , Barnard J. J.
Published: August 2014

Increased completion of ultra-deep, high-pressure and high-temperature wells is driven by the growing demand for hydrocarbons. Extreme pressure frac screens (XPFS) have been developed to handle the higher loads and conditions. An XPFS is a high-pressure-rated sand control screen capable of withstanding up to 15 ksi burst and collapse. The XPFS utilizes engineered, high-strength disintegrating materials (HSDM) to operate as a fluid-loss barrier that can be run-in on the liner. This new technology combines ease of use with a controlled delay in the activation that opens the screen to flow. The HSDM covers and seals over a bonded bead matrix that, when the HSDM dissolves, acts as a screen equal in filtration performance, but better than current sand control alternatives in its erosion resistance. The beaded matrix can be customized to ensure filtration through a wide range of particulate sizes and prevents passage of 85 to 90% of all particulates larger than 53µm. The HSDM covering the beaded matrix is formulated to corrode in the presence of brine and/or acid and provide access to the sand control media, enabling normal well production. The system increases the efficiency of hydraulic fracturing treatments, and can be installed in a steerable drilling liner. Alternatively, the beaded matrix can be replaced with a solid HSDM plug, thus acting as a fluid-loss friendly; solid-base pipe during run-in and leaving a pre-drilled liner after the HSDM dissolves, eliminating the expensive need to later perforate the pipe. This paper presents the pressure rating, dependability, and sand control capabilities of a liner that provides operators with an interventionless ability to complete ultra-deep, high-pressure high-temperature wells.
Gulf of Thailand Case Study: Improving Zonal Isolation with an Advanced yet Simplified Cementing System
Authors: Rivera N. N. , Siritheerasas K. , Valentino V. , Fauchille G. , Thein A. , Stanley R. , Brandl A.
Published: August 2014

The Gulf of Thailand is characterized by shallow-water depth wells with bottomhole static temperature ranging from 240 to more than 420°F. These wells are drilled to an average of 12,000 ft MD and 9,000 ft TVD with a fast paced-batch drilling strategy. Most cement jobs are done offline, and on the surface section can be as frequent as 6 jobs per day. With multiple rigs, operators can require more than 100 cementing operations per month and cement volumes as high as 18,000 bbl. This efficient operations environment creates a demand for a logistically and operationally simple cement system that can be applied in all well sections and across the full range of expected temperatures. An advanced, lightweight seawater-based cementing concept was tested for this application. This new cementing system uses a single blend with only 3 to 4 primary liquid additives (including a stable, high-temperature, multi-functional polymer) to adjust all primary cement jobs for the entire wellbore. A sophisticated lab testing program was conducted for the innovative cementing concept according to the required demands on cement slurry design given the harsh wellbore conditions in the Gulf of Thailand. Tests revealed that the developed cementing systems meet all well requirements despite low densities of 13.3 to 14.0 ppg with high water content. This advanced cementing system was introduced in 2011 and has gradually been used on all wells since then – to date more than 500 wells in the Gulf of Thailand. In addition to improving logistics, use of the system has enhanced cement bond quality in production tubing cementing jobs. This improvement also reduced pay at risk due to insufficient cement isolation. This is evident in the whole range of well temperatures.
Advanced Technologies and Practical Solutions for Challenging Drilling Applications
Authors: Jellison M. J. , Chan A.
Published: August 2014

This paper provides a review of recent technology advancements and addresses practical considerations associated with drillpipe and drill stem components for extreme drilling applications. Ultra-high torque double-shoulder rotary connections are often employed in these applications. Recent developments and enchantments in these connection designs including new higher strength materials, advanced thread forms and associated improvements in torsional strength and fatigue performance are presented. Deepwater wells frequently require long, heavy casing strings to achieve the total depth objectives. High capacity landing strings capable of running these heavy strings with total hook loads approaching 2.5 million pounds have been successfully developed to address this well design challenge. The paper discusses the engineering solutions implemented to overcome the high forces, slip crushing concerns and material strength and toughness considerations for these critical applications.

Due to the dramatic increase in oil prices the industry has seen a re-emergence of deep and ultra-deep drilling projects that encounter H2S gas. The paper provides an update on the latest sulphide stress cracking (SSC) resistant drillpipe grades including the first fully SSC resistant drill pipe system with SSC resistant friction welds joining the drill pipe tubes and tool joints. Major operators have been using a drill pipe based riser system for intervention and completion work in the waters offshore Brazil, Australia, Africa and other deepwater basins around the world. The paper provides updates on design improvements of high pressure capacity connectors and advanced materials for these critical riser applications.

Deepwater and other critical wells often encounter abrasive formations, high side loads between the drill string and bore hole and other conditions that promote drill stem friction heating failures. The paper includes characteristic features of these failures along with case histories and prevention methods.
Disappearing Tubing Hanger Plug (DTHP) Improves Well Integrity and Saves Rig Time for Deepwater Well Completions
Authors: Sevatdal Sigmund , Chanaani Rachid , Koay Darren
Published: August 2014

Traditionally, to complete a subsea well with a vertical Christmas tree, it is necessary to land the tubing hanger and install and pressure test a wireline set tubing hanger plug. Once the plug is tested, the subsea BOP can be removed, the vertical Christmas tree can be installed, and the plug retrieved through the work-over riser before the well is ready for production or injection. This is a time consuming rig operation requiring additional handling of the work-over riser and wireline run, which increases both the HSE and operational risks. With increasing focus being placed on the safety, reliability and cost efficiency of deepwater developments, it is critical that the operational risk and rig time for drilling and completions is reduced.

This paper describes the innovative invention of a shallow set barrier plug – the Disappearing Tubing Hanger Plug (DTHP) – and includes a case study of the first application of the plug on Akpo-214. This ground-breaking solution, based on knowledge of the existing glass barrier plug technology, was developed through a collaboration between Total E&P Nigeria and TCO. The objective of the invention is to provide a more reliable and cost effective solution for deepwater completions offshore of Nigeria.

The application of the DTHP has proven that the disappearing feature of the DTHP with pressure cycling is effective and reliable. The pressure cycle was applied directly from the FPSO, liberating the expensive rig for other purposes. The DTHP also provides improved well integrity by forming an ISO14310 V0 qualified gas-tight barrier. The operator saved rig time for the first installation and the rig time saving is estimated to be mutiple days for an optimized completin sequence on deepwater applications, which directly translates into savings of millions of USD.
Identifying a Reliable Boredom Induction
Authors: Markey Amanda , Chin Alycia , Vanepps Eric M. , Loewenstein George
Published: August 2014

None of the tasks used to induce boredom have undergone rigorous psychometric validation, which creates potential problems for operational equivalence, comparisons across studies, statistical power, and confounding results. This methodological concern was addressed by testing and comparing the effectiveness of six 5-min. computerized boredom inductions (peg turning, audio, video, signature matching, one-back, and an air traffic control task). The tasks were evaluated using standard criteria for emotion inductions: intensity and discreteness. Intensity, the amount of boredom elicited, was measured using a subset of the Multidimensional State Boredom Scale. Discreteness, the extent to which the task elicited boredom and did not elicit other emotions, was measured using a modification of the Differential Emotion Scale. In both a laboratory setting (Study 1; N = 241) and an online setting with Amazon Mechanical Turk workers (Study 2; N = 416), participants were randomly assigned to one of seven tasks (six boredom tasks or a comparison task, a clip from Planet Earth) before rating their boredom using the MSBS and other emotions using the modified DES. In both studies, each task had significantly higher intensity and discreteness than the comparison task, with moderate to large effect sizes. The peg-turning task outperformed the other tasks in both intensity and discreteness, making it the recommended induction. Identification of reliable and valid boredom inductions and systematic comparison of their relative results should help advance state boredom research.
Whole Exome Sequencing of Extreme Morbid Obesity Patients: Translational Implications for Obesity and Related Disorders
Authors: Paz-Filho Gilberto , Boguszewski Margaret , Mastronardi Claudio , Patel Hardip , Johar Angad , Chuah Aaron , Huttley Gavin , Boguszewski Cesar , Wong Ma-Li , Arcos-Burgos Mauricio , Licinio Julio
Published: August 2014

Whole-exome sequencing (WES) is a new tool that allows the rapid, inexpensive and accurate exploration of Mendelian and complex diseases, such as obesity. To identify sequence variants associated with obesity, we performed WES of family trios of one male teenager and one female child with severe early-onset obesity. Additionally, the teenager patient had hypopituitarism and hyperprolactinaemia. A comprehensive bioinformatics analysis found de novo and compound heterozygote sequence variants with a damaging effect on genes previously associated with obesity in mice (LRP2) and humans (UCP2), among other intriguing mutations affecting ciliary function (DNAAF1). A gene ontology and pathway analysis of genes harbouring mutations resulted in the significant identification of overrepresented pathways related to ATP/ITP (adenosine/inosine triphosphate) metabolism and, in general, to the regulation of lipid metabolism. We discuss the clinical and physiological consequences of these mutations and the importance of these findings for either the clinical assessment or eventual treatment of morbid obesity.
How Should Community Mental Health of Intellectual Disability Services Evolve?
Authors: Hemmings Colin , Bouras Nick , Craig Tom
Published: August 2014

Services for people with Intellectual Disability (ID) and coexisting mental health problems remain undeveloped; research into their effectiveness has been lacking. Three linked recent studies in the UK have provided evidence on essential service provision from staff, service users and carers. Interfaces with mainstream mental health services were seen as problematic: the area of crisis response was seen as a particular problem. Further services’ research is needed, focusing on service components rather than whole service configurations. There was not support for establishing more intensive mental health services for people with ID only. The way forward is in developing new ways of co-working with staff in “mainstream” mental health services. Mental health of ID staff might often be best situated directly within these services.
Mineral Resource Dilemma: How to Balance the Interests of Government, Local Communities and Abiotic Nature
Authors: Nikitina Nataliya
Published: August 2014

It is noted that over the last few years the implementation of several mineral exploration, development and mining projects has been suspended and even completely stopped due to resistance from local communities. The key concerns of local residents typically include perceived or real impact of mining enterprises on the environment, unfair distribution of profits from mining and exploration activities, insufficient contributions to local government budgets and lack of transparency regarding ultimate ownership of companies conducting exploration and mining. The article looks at social conflicts of this kind and suggests some alternative solutions that could prevent such conflicts at the stage of granting exploration and mining rights.
Estimating Forest Aboveground Biomass by Combining ALOS PALSAR and WorldView-2 Data: A Case Study at Purple Mountain National Park, Nanjing, China
Authors: Deng Songqiu , Katoh Masato , Guan Qingwei , Yin Na , Li Mingyang
Published: August 2014

Enhanced methods are required for mapping the forest aboveground biomass (AGB) over a large area in Chinese forests. This study attempted to develop an improved approach to retrieving biomass by combining PALSAR (Phased Array type L-band Synthetic Aperture Radar) and WorldView-2 data. A total of 33 variables with potential correlations with forest biomass were extracted from the above data. However, these parameters had poor fits to the observed biomass. Accordingly, the synergies of several variables were explored to identify improved relationships with the AGB. Using principal component analysis and multivariate linear regression (MLR), the accuracies of the biomass estimates obtained using PALSAR and WorldView-2 data were improved to approximately 65% to 71%. In addition, using the additional dataset developed from the fusion of FBD (fine beam dual-polarization) and WorldView-2 data improved the performance to 79% with an RMSE (root mean square error) of 35.13 Mg/ha when using the MLR method. Moreover, a further improvement (R2 = 0.89, relative RMSE = 17.08%) was obtained by combining all the variables mentioned above. For the purpose of comparison with MLR, a neural network approach was also used to estimate the biomass. However, this approach did not produce significant improvements in the AGB estimates. Consequently, the final MLR model was recommended to map the AGB of the study area. Finally, analyses of estimated error in distinguishing forest types and vertical structures suggested that the RMSE decreases gradually from broad-leaved to coniferous to mixed forest. In terms of different vertical structures (VS), VS3 has a high error because the forest lacks undergrowth trees, while VS4 forest, which has approximately the same amounts of stems in each of the three DBH (diameter at breast height) classes (DBH > 20, 10 ≤ DBH ≤ 20, and DBH < 10 cm), has the lowest RMSE. This study demonstrates that the combination of PALSAR and WorldView-2 data is a promising approach to improve biomass estimation.
Okinalysin, a Novel P-I Metalloproteinase from Ovophis okinavensis: Biological Properties and Effect on Vascular Endothelial Cells
Authors: Komori Yumiko , Murakami Eri , Uchiya Kei-ichi , Nonogaki Tunemasa , Nikai Toshiaki
Published: August 2014

A novel hemorrhagic metalloproteinase, okinalysin, was isolated from the venom of Ovophis okinavensis. It possessed caseinolytic and hemorrhagic activities, and also hydrolyzed fibrinogen and collagen. These activities were inhibited by ethylenediaminetetraacetic acid (EDTA) but not by p-amidinophenyl methanesulfonyl fluoride hydrochloride (APMSF). The molecular mass of okinalysin was 22,202 Da measured by MALDI/TOF mass spectrometry. The primary structure of okinalysin was partially determined by Edman sequencing, and the putative zinc-binding domain HEXXHXXGXXH was found to be present in its structure. From these data, okinalysin is defined as a metalloproteinase belonging to a P-I class. The partial amino acid sequence of okinalysin was homologous to the C-terminus of MP 10, a putative metalloproteinase induced from transcriptome of the venom gland cDNA sequencing of O. okinavensis. Okinalysin possessed cytotoxic activity on cultured endothelial cells, and the EC50 on human pulmonary artery endothelial cells was determined to be 0.6 μg/mL. The histopathological study also showed that okinalysin causes the leakage of red blood cells and neutrophil infiltration. These results indicate that destruction of blood vessels by okinalysin is one of the main causes of hemorrhage.
Restructuring of an Ir(210) electrode surface by potential cycling
Authors: Soliman Khaled A , Kolb Dieter M , Kibler Ludwig A , Jacob Timo
Published: August 2014

This study addresses the electrochemical surface faceting and restructuring of Ir(210) single crystal electrodes. Cyclic voltammetry measurements and in situ scanning tunnelling microscopy are used to probe structural changes and variations in the electrochemical behaviour after potential cycling of Ir(210) in 0.1 M H2SO4. Faceted structures are obtained electrochemically as a function of time by cycling at a scanrate of 1 V·s−1 between −0.28 and 0.70 V vs SCE, i.e., between the onset of hydrogen evolution and the surface oxidation regime. The electrochemical behaviour in sulfuric acid solution is compared with that of thermally faceted Ir(210), which shows a sharp characteristic voltammetric peak for (311) facets. Structures similar to thermally-induced faceted Ir(210) are obtained electrochemically, which typically correspond to polyoriented facets at nano-pyramids. These structures grow anisotropically in a preferred direction and reach a height of about 5 nm after 4 h of cycling. The structural changes are reflected in variations of the electrocatalytic activity towards carbon monoxide adlayer oxidation.
Calvia explanata sp. n. (Coleoptera: Coccinellidae: Coccinellinae) from the Indian Subcontinent
Authors: Poorani J.
Published: August 2014

Calvia explanata sp. n. (Coleoptera: Coccinellidae), externally similar to and commonly misidentified as C. albida Bielawski, is described from India and Nepal.