bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using Engineered Fiber Pills to Cure Losses in Carbonate Formations - Offshore Deepwater Kenya
Authors: Awalt Michael S. , Mujuni Philbertus Deogratias , Johnson Carl , Joneja Galen , Meyer Arnoud , Bonsu-Gyimah Maame Serwaa , Hernandez Jonatan Torres 
Published: March 2016

Abstract
In line with the rise in remote deepwater exploratory work in East Africa, a major operator drilled a well in one of the two petroleum block licenses that they own offshore Kenya. The well was drilled in a water depth of 723m (2372ft) with the primary objective of establishing the presence of net pay and fluid type at specified stratigraphic levels. Prior to spud, the geological prognosis of the well indicated the presence of carbonate formation characterized with vugs and the imminent risk of severe losses were predicted. The drilling of this well indeed proved to be a challenging process.
Lost circulation while drilling and cementing continues to be a consistent problem in most deepwater operations that costs significant time and money. Firstly, the operator is faced with the inability to reach planned total well depth within the projected time interval, and secondly the necessary hydraulic isolation (cementation) covering problematic formations is not achieved.
In addressing the loss and weak zones, different approaches are used notably by reducing the hydrostatic pressure column, utilizing lighter weight slurries and reducing the penetration of fluids into fractures with the use of lost circulation material.
Losses were encountered in all hole sections below the 20-in casing just as predicted; estimated between 40 to 180 bbl/hr. As per a planned line of action, the mud service company pumped a range of lost circulation materials with different formulations, but none was successful. The executed approach was not effective in curing the losses and this resulted in total down time of 16 days of rig time causing the operator an additional $20 million over the AFE. Out of this additional cost, $0.34 million was due to mud lost into the formation and the rest was for daily operating rig cost.
The extent of the losses was so severe that it took a total of three engineered fiber pills and cement plugs placed at different depths before the operator could drill beyond the troubled zones. This paper is intended to cover the use of an engineered fiber and solids technology in a spacer system that was pumped ahead of cement slurry to aid in curing the losses.
Evaluation of Highly Retarded Cement Systems Under Exposure to Radiation Sources for Oilfield Applications
Authors: Lewis S. , Funkhouser G. P. , Gupta V. 
Published: March 2016

Abstract
Cement slurries have been designed to remain liquid for extended periods of time (&gt; weeks) until exposed to a radiation source to provide a triggered activation mechanism. The cement setting occurs in two stages. First, a triggered setting of an aqueous phase system forms a stiff gel; then, the gel hardens further and develops strength because of cement hydration. The initial set can be accomplished by means of the triggered mechanism, while final engineering properties are provided by the hardened cement.
This paper describes the design and results of this initial work detailing the rheological behavior and mechanical properties of cement slurries on exposure to 14 MeV neutron radiation from an accelerator and ionizing sources currently used in wellbore logging, such as gamma radiation.
Additionally, other radiation sources are described in terms of their potential for use in a wellbore environment.
The triggered response of this system with relation to neutron energy and admixtures used in the cement design to impart direct response is discussed. Particular details are presented relative to usage of commercially available radiation sources and their efficacy in a wellbore environment. Correlations between energy output, calculated energy absorption, and cement response summarize the effects of this ionizing radiation on cement slurries containing admixtures designed to respond to such exposure.
The discussed cement systems employ monomer and polymer chemistry specifically selected for use with radiation triggered systems. Use of these chemistries in cement as additives and in other systems, such as spacer fluids or drilling fluids, is demonstrated.
Maximize Investment Rewards : Investigating the Effect of Field Characteristic on the Optimal Subsea Processing Solution
Authors: Sandy D. , Hasan Z. 
Published: March 2016

Abstract
Meeting the objective shared by all offshore oil and gas companies – maximizing reservoir production and recovery – is constantly challenged by a growing host of market issues and technology risks. When producing new offshore fields, operators face increasing challenges including deepwater, low reservoir pressure, heavy oil and long-distance step-outs. And it is not just in the development of new offshore fields that challenges are faced. Declining oil & gas production, increasing water cut with constrained topside facilities, increasing flow assurance challenges, growing operating costs, and integrity challenges due to aging facilities are all factors that can lead to field becoming operationally and economically unviable.
Subsea processing technologies are being adopted to address these challenges, especially in extreme environments. Subsea separation and boosting, for example, have not only proven their ability to enable complex developments with reliable performance levels, but have also delivered financial value.
In evaluating any subsea processing system, proven or new, investment rewards must be carefully investigated to ensure that the introduction of an advanced subsea solution will accelerate reserves, increase production and reduce costs. Field characteristics such as step-out distance, formation water production, fluid properties and water depth are some of the factors that must be assessed as part of the reward assessment.
This paper investigates how the step-out distance and formation water production affects the optimal subsea processing solution. Three different configurations will be considered; natural flow, subsea multiphase boosting, and subsea separation with separate gas and liquids pipelines.
Lightweight Drilling Riser Achieves 12 Years Successful Operation in Offshore Brazil
Authors: Lehner Jeffry K , Barker Ian , Walters David 
Published: March 2016

Abstract
This paper evaluates the application of lightweight drilling riser systems, comprised of aluminum alloy material that is significantly lighter than steel riser systems. The paper describes the system's design and specifications, and presents operational and maintenance procedures particular to lightweight riser use. The paper evaluates the comparative costs and benefits of upgrading a rig versus using lightweight alloy risers to increase water depth capability, and reviews the performance of these systems after more than a decade of operation.
The first lightweight alloy drilling riser system was deployed in Brazil in 20031. The initial aluminum alloy riser replaced a steel riser on a drill ship to reduce riser weight by 30% and increase the rig's water depth capacity by 2,000 ft. By the end of 2005, lightweight riser systems were deployed on another drill ship and two semisubmersible rigs, also working in Brazilian waters. By switching to lightweight risers, these units could operate in deeper waters without undergoing expensive upgrades. The lightweight riser systems on three rigs of the original rigs are still in use and continue to be in excellent condition.
As water depths increase, risers for drill ships and semisubmersible rigs become some of the most critical components of the drilling operation. Risers must be strong enough to maintain integrity during deployment and operation, be light enough to be handled and supported by the floating drilling unit, and be constructed of materials that resist corrosion while exposed to seawater. Lightweight alloy risers provide a means of increasing the water depth rating of floating rigs by as much as 50% without requiring expensive upgrades. Because of their lightweight construction, alloy risers are easier to handle, require fewer buoyancy modules, and can enable earlier generation floating rigs to increase their water depth capabilities, when compared to using conventional steel risers. The first generation of lightweight deepwater (DW) alloy risers has been used successfully for more than a decade while drilling in water depths up to 7,200 ft.
Optimizing the Lithology and Pore Fluid Separation Using Attenuation Attributes
Authors: Hermana Maman , Ghosh Deva P. , Sum Chow Weng 
Published: March 2016

Abstract
Ambiguity and pitfalls in amplitude interpretation to determine the hydrocarbon prospects is the most challenging problem in oil and gas industry, including in the Malay Basin Field. These pitfalls are caused by a dualism of the lithological and pore fluid effect on seismic amplitude. Many techniques have been proposed to solve the problem. However, the optimum separation of that ambiguity is still difficult to be achieved. The objective of this paper is to demonstrate new attributes derived from seismic attenuation - rock physics approximation as an alternative technique for lithology and pore fluid discrimination.
New attributes namely SQp and SQs have been developed based on seismic attenuation-rock physics approximation. Testing on model and real data sets from Malay Basin have been conducted.
The results show that the SQs attribute is sensitive to the water saturation changes, while the SQp is sensitive to the lithology changes. In well log, the SQs attribute has the highest coefficient correlation with water saturation compared with other existing fluid indicators, while SQp attribute has the highest correlation with gamma ray log. The cross plotting of these attributes show that the lithology and pore fluid effect are separated orthogonally to each other. The lithology differences are distinguished in the SQp attribute, while the fluid types are distinguished in SQs attribute. The gas sand is separable from shale background and wet sand easily. Furthermore, the coal effect can be distinguished clearly from gas sand. The implementation of those attributes on inversion result shows that SQs attribute is able to delineate the gas sand from wet sand that cannot be done by SQp attribute. Meanwhile, the SQp attribute can capture all the sand formations including gas sand and wet sand which is distinguished from shale background.
Reel-Lay Installation Approaches for Mechanically Lined Pipes
Authors: Tkaczyk Tomasz , Chalmers Martin , Pépin Aurélien 
Published: March 2016

Abstract
An increasing demand for subsea transport of corrosive constituents has generated interest in bi-metal pipes, which are made of a carbon steel pipe lined with corrosion resistant alloy (CRA). The CRA layer can be adhered to the backing steel pipe by either metallurgical or mechanical means. Reel-lay is an efficient installation method for subsea pipelines but induces plastic straining that may trigger wrinkling of the CRA liner in mechanically lined pipe (MLP), if reeling is not properly managed. Therefore, a suite of installation approaches has been qualified to enable safe reeling of MLPs. To provide evidence that a high fatigue performance can be achieved by reeled MLPs, a series of qualification tests has been undertaken. Finally, a thorough industrialisation of MLP manufacturing processes has been completed to ensure that defect-free MLPs can be manufactured in large quantities.
Combining Sonic While Drilling and Formation Pressure While Drilling for Pore Pressure Analysis to Reduce Drilling Risk: A Case Study in Offshore Vietnam
Authors: Dac The Nguyen , My Dung Doan Thi , Ahmed Aqil , Thai Ha Phung , Rehman Sadu-ur , Truong Son Nguyen , Hong Giang Khuc 
Published: March 2016

Abstract
The accurate prediction of pore pressure is important for safe drilling and can reduce financial risk significantly. The major focus during drilling in a high-temperature/high-pressure (HP/HT) environment is optimizing the drilling operation to mitigate risk by utilizing data such as sonic logging-while-drilling (LWD) and offset well information.
An offshore exploration well was being drilled in offshore Vietnam with drilling challenges of abnormally high formation pressure. In normally compacting sediments, water escapes through permeable sands or along fractures as overburden sediments build up, and fluid or pore pressure remains close to hydrostatic pressure. In such normally compacting sediments, under increasing effective pressure, porosity decreases and compressional velocity increases. However, if formation fluids cannot escape, for example due to the low permeability of overlying shales, then they bear part of the overburden load and hence become overpressured. These formations are called undercompacted, meaning they have a higher porosity than normally compacted shales. In overpressured shales, which contain pressured water, density is lower, porosity is higher, and compressional velocity is lower than normal.
Formation pressure can be the major factor affecting the success of drilling operations. If pressure is not properly evaluated, it can lead to drilling problems such as lost circulation, kick, stuck pipe, hole instability, and excessive costs. Therefore, knowledge of the pore pressure is of considerable value because it provides the means for improving drilling operations and designing better casing programs to reduce those risks. Using the data gathered from well logs, it is possible to predict the probable pressure profile that will be encountered while drilling. LWD data enable monitoring pore pressure very effectively; this pore pressure prediction can be continuously updated using LWD sonic and formation pressure while drilling (FPWD) to make optimal decisions for drilling operation. Once a suitable predrill pressure profile is established, it is monitored on the current wells with while drilling sonic and directly calibrated with formation pressures taken in sands.
In the offshore Vietnam well, pore pressure monitoring by LWD formation pressures and estimated pore pressure from LWD sonic data allowed drilling operations to be optimized. Employing this technique led to successful drilling without any incidences related to pore pressure. The computed pressures from LWD sonic matched the measured pressures obtained from FPWD. The real-time sonic matched the recorded-mode sonic closely. This technique could apply not only to the wells in this basin but also to the other wells in the locations with abnormal high formation pressure.
Reestablishing the Norms - Realizing Savings from Optimizations of Malaysian Drilling Industry
Authors: Sulaiman Muhammad Zarkashi , Hakim Hazlan A. , Hiep Nguyen Hong 
Published: March 2016

Abstract
This paper outlines the Low Cost Drilling (LCD) initiative rolled out in support of Cost Reduction Alliance 2.0 (CORAL 2.0) launched by Malaysia Petroleum Management (MPM), the regulatory body of PETRONAS, to propagate the practices of twenty six (26) Value Levers identified under four (4) key areas that could potentially lower the wells costs by Petroleum Arrangement Contractors (PACs) in Malaysia, with targeted savings of MYR 850 million from planned one hundred twenty five (125) wells in 2015.
Malaysian Oil & Gas industry has evolved from 3-4 PACs back in 1990s to over 25 PACs by 2014. Similarly, the number of wells drilled each year continue to rise to meet the production target. The average well cost has steadily increased annually due to inflation and increasing demand over supply for drilling tools and services. In 2014, Drilling & Well Intervention (DWI) section or widely known as MPM Drilling, under Petroleum Operations Management (POM) of MPM, has embarked on a study of the "Best In Class" over low cost wells delivered for the past two (2) years by PACs in Malaysia.
A total of twenty six (26) Value Levers were identified in the overall findings which could be categorized under four (4) key areas; 1) Planning & Well Design (12 elements), 2) Operational Practices (10 elements), 3) Fit for purpose technology (1 element), and 4) Logistics Operation (3 elements).
The initiative was rolled out in February 2015 by MPM Drilling in support of CORAL 2.0, where PACs were requested to identify Value Levers that could be applied to their wells with estimated potential cost savings. Twelve (12) PACs have responded with total targeted savings of MYR 850 million over 125 wells planned for 2015. This averaged to a cost reduction of around MYR 6.8 million per well. The progress savings will be monitored on quarterly basis against the initial target. Actual realized savings for 2015 will be confirmed in Quarter 1, 2016.
Overcoming Wellbore Instability Challenges in HPHT Field with Fully Coupled Poro-Thermo-Elastic Modeling: A Case Study in Hai Thach Field Offshore Vietnam
Authors: Hoang Son K. , Nguyen Son T. , Khuc Giang H. , Nguyen Duc A. , Abousleiman Younane N. 
Published: March 2016

Abstract
In this study, fully coupled poro-thermo-elastic geomechanics modeling of wellbore stability was conducted on high pressure and high temperature (HPHT) wells in Hai Thach field offshore Vietnam. The drilling environment is extremely challenging with formation pore pressure gradient of more than 17.0 ppg and formation temperature above 170°C near TD. Post-mortem analyses of drilled wells were carried out using an analytical poro-thermo-elastic wellbore stability simulator, taking into account the coupled time-dependent evolution of pore pressure, temperature, and stresses around the wellbore. The analyses revealed very narrow time-dependent safe mud weight windows that became narrower as time progressed. The HPHT environment created very challenging drilling situations. During drilling and hole cleaning, the flowing mud cools off rock formations, inducing tensile thermal stresses, and therefore reducing effective compressive stresses around the wellbore. As a consequence, the fracturing pressure is reduced when the ECD is higher due to circulation, increasing the chances of mud losses. On the other hand, during static mud condition the formations retain their very high temperature and compressive stresses, which require higher mud weight to prevent wellbore collapse while the mud pressure only equals the static mud weight, increasing the chances of shear failure. This study highlights the importance of accurate prediction of safe mud weight window before drilling as well as timely updates to the mud weight window during drilling. Furthermore, guidelines of good mud weight management practices to drill the HPHT zones with very narrow mud weight windows are also given. For example, when the safe mud weight window is too narrow and shrinks with time, a higher static mud weight might be required during openhole logging to combat borehole collapse. On the other hand, during hole cleaning with increased mud circulation rate and increased ECD, a lower static mud weight might be required to mitigate mud losses. Moreover, with the time-dependent safe mud window available, the drilling and logging program can be optimized to minimize exposure time and mitigate the damaging thermal effects on the mechanical stability of the drilled borehole.
Multiscale Modelling Approaches for Flexible Risers: Procedures, Capabilities and Demonstrations
Authors: Edmans B. D. , Guo T. , Zhang Z. , Pham D. C. , Sridhar N. , Stewart G. 
Published: March 2016

Abstract
Unbonded flexible risers are key components in many offshore oil and gas developments. To evaluate their performance, accurate mechanical models and efficient analysis techniques are required, both for life extension assessments of existing assets and for determining safe operational envelopes of new designs in deepwater environments. Due to the structural complexity of unbonded flexible pipes, predicting stresses and instability failures in these components remains challenging, inviting new approaches. This paper presents developments in the consistent linking of small scale (local nonlinear structural analysis) and large scale (global dynamic analysis). We describe sequential and integrated multiscale formulations aimed at improving modelling accuracy in a computationally feasible form. Principles and procedures for consistent multi-scaling are outlined based on established techniques used for the modelling of composite materials and structures that exhibit periodic symmetry and results are presented using these methods.
The predictive capabilities of the components of the multiscale analysis are explored, including: 1) a nonlinear beam-type finite element for riser representation; 2) a novel nonlinear section response model; and 3) a detailed finite element model computing component interactions. Verification of the integrated multiscale procedure is shown for a simplified case. The utility of multiscale models for investigating the conditions that lead to mechanical instability failures, such as buckling of the tensile armour wires is also discussed. The analysis procedures and model described in this article are proposed as methodologies for assessing fatigue damage, predicting instability failure modes and investigating the consequences of damage, such as breaking of tensile armour wires.
A Review: Operational Perspective into Cohesive Design of Offshore Facilities
Authors: Chandrasegaran D. , Noor M. H. Mohd , Sevah S. , Lok E. T. 
Published: March 2016

Abstract
Offshore facilities have diverse operational requirements due to the difference in user populations and the design intent of the facilities. Most facilities design is focused on the process requirements rather than the operations of the facilities. This paper focuses on the operational perspective in the design of offshore facilities. The term operational perspective covers all handling of materials, human machine interfaces and managing people in offshore facilities.
General operational concerns are described briefly. The operational needs such as handling provisions, human factors and regulatory compliance for the offshore facilities are summarized based on the current practices. Also, recent development and engineering practices in the offshore facilities operation are elaborated. Usage of human factors tools and others operational studies in design development activities are discussed as well.
As identified during the review, there is a common aim from operational and process that is to produce a reliable and safe facilities design. Any apparent gap between the operational requirements and current offshore facilities design products may result in low efficiency, higher risks exposure and lost time injuries. And these would be faced by the operator through the facilities life. In addition, there is a growing demand in the industry that stresses lower manning in the facilities, focused on operational needs and safety culture. Therefore, a cohesive approach during early design phase is required in addressing these gaps.
Systematic approaches are elaborated in this paper during early design phase to create better solutions and reducing modification works throughout the facilities life.