bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamic Analysis Including Shielding Effects and Advanced DP Controls for Improved Uptime of a Floatel Connected to an FPSO by a Gangway
Authors: Cong P. -W. , Magee A. R. , Jaiman R. , Ge S. -Z. , Zhang Q. , Tu F. -W. , Choudhary A. , Merchant A. , Hussain A. , Xu W.
Published: March 2018

As the offshore oil and gas industry seeks to reduce costs, a semi-submersible floatel, which provides the space for crew accommodation and open deck space for the necessary equipment, is used to perform maintenance instead of returning the FPSO to a shipyard. One of the unavoidable challenge we have to cope with is the large amount of shielding effects due to the FPSO in the vicinity. The objective of this study is to understand the hydrodynamic interactions and flow interference between them, which will help to develop a comprehensive numerical tool to predict the motion behavior and help designers increase the operability window.

Firstly, the second-order diffraction program is used to evaluate hydrodynamic coefficients for a system composed of a floatel operating close to a turret moored FPSO. The calculation is carried out according to different relative positions and yaw angles between the vessels to assess the second-order nonlinear effects and the shielding effects due to waves. Secondly, CFD (computational fluid dynamics) software is used to determine the drag force coefficients due to current and the shielding effects for the two bodies. Numerical studies of thrusterthruster and thruster-hull interactions on unsteady loads are also conducted based on CFD numerical tools. Thirdly, a PID control scheme is used to control low-frequency relative position and orientation between the two bodies. Finally, using the wave, wind and current force coefficients and feedback of DP control system, the global motions of the two vessels in non-parallel environmental conditions are numerically simulated.

By using this numerical tool, the shielding effect between a floatel and a FPSO is studied in detail, and all the nonlinearities of the problem can be assessed. New understanding is created through the parametric study, by which useful physics-based information can be provided to optimize the length requirement of gangway and help the operator to decide on the safe working operational scenario.

The number of aging FPSO installations worldwide is increasing every year. These FPSOs are connected with massive permanent riser systems and mooring system and it is very costly to bring them to the dry dock for maintenance. By accurately estimating the interactions and shielding effects, improved predictions models are being developed which can increase the up-time of the floatel by up to 20%. This opens up new opportunities for on-site FPSO maintenance with reduced costs.
The Mid Atlantic Current Hindcast MACH
Authors: Stephens R. V. , O'Neill C. K. , Siddorn J. R. , Cox A. T. , Harris E. , Orelup E.
Published: March 2018

The objective was the generation of a long-term layered ocean current dataset for the central and southern Atlantic Ocean, of suitable quality to support deep water offshore engineering design, marine operational planning and oil spill simulation. A model scheme was formulated to provide a reference fine resolution offshore grid covering the Atlantic Ocean from 30 degrees north to the Antarctic land mass. Very fine resolution grids were nested to model the continental shelf and slope regions of principal interest for oil and gas exploration and production. Various schemes were evaluated for representation of the riverine discharge, which is of major importance in some parts of west Africa. Additionally, optimal data assimilation scheme formulation was considered in order to best represent ocean surface topography, registration of major dynamic features such as fronts and eddies, and also correct characterisation of ocean density structure. Particular attention has been given to the equatorial region where energetic Kelvin wave propagation is generated by wind forcing; such waves contribute significantly to the most severe ocean current speeds, but can be spuriously misrepresented by inappropriate assimilation of erroneous observational data. The computational runtime required to undertake a long-term ocean reanalysis was large, even when using a major supercomputing facility. Therefore, it was extremely important to ensure that the model configuration was optimised in a structured pilot evaluation in advance of the full production run in order to achieve ‘fitness for purpose’ for the intended applications of the resultant dataset. This paper discusses the detailed process of structured model optimisation, where various permutations of setup had been validated against available in-situ measurements. The final model has now been completed for a 20year run and has been used in a number of regional metocean studies for Oil and Gas clients. The inclusion of location specific processes offers significant advantages over previously existing models.
Underbalanced Nitrified Foam Drilling Enabled Extensive Reservoir Characterization and Production from a Highly Depleted Formation in Dhodak Field in Pakistan: A Case History
Authors: Khalid Ali , Ashraf Qasim , Luqman Khurram , Channa Munsif , Hussain Muhammad
Published: March 2018

The Dhodak field is located in the eastern Sulaiman Range in Pakistan. The first well drilled there in 1975 produced gas and condensate from the Pab sandstone intervals created in the Cretaceous Age. Drilling any well in the field results in severe circulation losses because of the younger carbonate horizons of the Eocene Age, which includes the Habib Rahi and Rubbly Limestone. Operators cure these losses by spotting lost-circulation material (LCM) pills and deploying numerous cement plugs. In one particular well in the Dhodak field, an operator encountered an unexpected well-control scenario when drilling through the Rubbly Limestone, which further confirmed the potential for hydrocarbons in the horizon.

To explore the potential of the Rubbly Limestone, the operator drilled a dedicated well named Rubbly-1 using a conventional mud system and, as expected, encountered total loss of circulation. Drilling continued to the target depth, with heavy LCM pills and four cement plugs to cure losses. A prospective production interval was identified, and subsequent drill stem testing (DST) was performed. The well did not flow in the DST even after numerous attempts to kick it off. An evaluation determined that bridging materials had extensively invaded the formation when attempting to cure losses. The invading materials had clogged the pores of the reservoir formation, which resulted in no production and subsequent abandonment of the well.

Underbalanced drilling provided a feasible solution that allowed the well to flow while drilling and eliminated overbalanced pressures and invasion damage. The reservoir pressure measured just 5 lb/gal (599 kg/m3) in equivalent mud weight. The low pressure of the formation meant it could only be drilled with a foam system.

A suitable foam system provided a low equivalent circulating density that enabled drilling the Rubbly Limestone formation. By applying an underbalanced nitrified foam system, the operator drilled the horizontal to the target depth (TD) without any issues. The well started flowing while drilling, and the operator evaluated the reservoir potential by performing surface testing and openhole wireline logging, which resulted in logs with excellent resolution. This paper details the design criteria, equipment selection, and wellsite execution program used for drilling and evaluating the Rubbly Limestone formation.
Improving the Competency Assessment and Verification Process for Wells Personnel Involved in Safety and Environmentally Critical Operations will Improve HSE Performance and Reduce Major Accident Incidents.
Authors: Kinkead Brian
Published: March 2018

This paper reviews present methods and shares best practice in conducting competency assessments, including their verification, for wells personnel involved in safety and environmentally critical operations with a view to improving HSE Performance and Reducing Major Accident Incidents.

The wells personnel included are those identified Oil & Gas UK (OGUK) as the minimum positions involved in safety and environmentally critical operations. This paper includes a review of the OGUK industry Guidelines on competency for wells personnel – Issue 2 (OGUK, 2017), a review of the assessment and verification procedures associated with the UK guidelines "Industry Guidelines for the Management of Competence and Training in Emergency Response for Offshore Installations – Issue 3, (OGUK, 2010) and other industry findings such as the Office of Railways Safety and Standards Board (ORR).

There is a wide variance on which direct and indirect assessment methods are used for different onshore and offshore positions. The paper draws conclusions on which methods work best for given positions, how assessors are trained to carry out assessments, the validity of using independent assessors and the benefits of standardizing certain elements of assessment.

A conclusion on the role that professional institutions, including the SPE, may play in the overall assessment of competence is examined. The wide variance of verification methods is reported on and recommendations made on their suitability. The potential for standardization of certain elements of the assessment and verification process will lead to savings, improved utilization of personnel and quality of assessments. Ensuring that assessments are of a common and consistent high standard will improve overall Health, Safety and Environmental performance and help reduce major accidents.
First Pressurized Mud Cap Drilling with Top Kill Application in Malaysia Development Wells
Authors: Idris M Faisal Rizal , Fabian Oka , Hua Lai Yen , Arathoon Mark , Musa M Zarir , Musa Syahirah , Johari M Raimi
Published: March 2018

In 2016 PETRONAS embarked on the challenge of drilling and completing high temperature, highly deviated fractured carbonate development wells using Pressurized Mud Cap Drilling (PMCD) techniques. With equivalent formation pressure gradients of 13ppg, H2S levels of 140ppm and formations with potential for massive losses, but also very high gas productivity, severe challenges were presented to the drilling engineering and operations teams and to the logistical infrastructure; these challenges were successfully overcome, ensuring that the wells were delivered safely using the planned Tender Assisted Drilling Rig.

Maintaining well control integrity throughout all drilling and completion operations is always crucial to ensuring safe well delivery. In wells with total losses, drilled through highly productive carbonate formations, there is a high risk that any loss of the primary drilling fluid barrier may result in the well flipping out to gas very rapidly. This risk is highest during trips out of the hole, when the Rotating Control Device (RCD) pressure seal must be removed to retrieve the drilling BHA and run the lower completion. For wells with total losses, options to control the well during trips have traditionally involved a combination of methods including setting gunk plugs, setting composite bridge plugs, or using a preinstalled Downhole Isolation Valve.

The purpose of this paper is to present a fourth option, the top-kill method using a dual-density fluid system. During the 2015-2016 PETRONAS development drilling campaign, following thorough risk assessments and detailed planning and logistical evaluation, this method was proven to be a reliable and safe means of controlling the well during trips.

A total of five (5) wells were drilled from the development platform, using a surface BOP stack and an RCD. Top kill operations were engineered by pumping two types of fluid into the annulus at surface; a slightly underbalanced Light Annular Mud and a heavier density Kill Mud. By combining these fluids, the well was put into an engineered overbalanced state, with the loss rate controlled via a pre-determined pumping rate. Once the RCD seal element was re-installed, the well reverted back to pumping Light Annular Mud into the annulus as per normal PMCD procedures.

This paper highlights the meticulous planning, execution, training and continuous learning that was evident in these challenging operations. This paper also discusses critical HSE concerns and makes recommendations for future PMCD projects.
Enabling SIMOPS from Jack-Ups
Authors: Zijderveld G. H. T. , Bonte S. J. , Tiebout J. J.
Published: March 2018

In today's environment drilling, well workover and well intervention operations call for increased efficiency and safety. Concurrent operations are a method to increase efficiency. However safety should not be compromised. An innovative device has been developed to enable SIMOPS (Simultaneous Operations) from a jack-up.

An analysis has been made to identify which operations, when executed from a jack-up, would benefit from the possibility to be done concurrently. Typically most well operations are done through the rotary table. Those operations are either using drillpipe, wireline or coiled tubing. The operations are thus often sequential and allow for working at one well at the time.

On production platforms with multiple wells it would be of interest to work on more than one well at the time. For example working on one well with drillpipe while working on another well with wireline or coiled tubing. Also the setting and retrieval of temporary plugs can be done faster while not compromising safety.

While the primary load path on a jack-up is through the rotary table some operations do not really require the high lifting and lowering capacity which is offered by the topdrive assembly in the derrick. Especially for wireline and coiled tubing operations the lifting and lowering capacity can be much lower.

So an add-on device with reduced load capacity which enables non-drillpipe operations can be advantageous. Especially when it can be working free of obstructions under the cantilever of the jack-up.

The new add-on device will increase rig efficiency during development drilling, well workover/intervention and plug & abandonment operations. It for instance enables wireline guidance into the well through its moveable arm with the hoisting point below the cantilever. This while other operations on an adjacent well are executed simultaneously through the rotary table.
Nano-Sized Particle as Foam Stabiliser Designed for Application at High Temperature and Light Crude Oil Condition for Enhanced Oil Recovery - A Fluid-Fluid Case Study
Authors: Razali Norzafirah , Hsia Ivy Chai Ching , Zainal Suzalina , Manap Arif Azhan A
Published: March 2018

Foam Assisted Water-Alternating-Gas (FAWAG) flooding is one of the enhanced oil recovery (EOR) technique that had been explored and studied worldwide. The ability of foam to lower the gravity override and create a macroscopic sweeping of oil in the reservoir shows its potential to be a successful technique. However, the rapid degradation of foam at high temperature condition in the presence of light crude oil limits its application. Therefore, introduction of an additive to the surfactant is crucial to maintain foam stability. Nano-scale particle is a well-known material that has attracted a lot of attention due to its unique physiochemical properties. This high surface energy particle has shown to exhibit a catalytic behaviour in various application including EOR chemical flooding. In this study, the effect of four different types of nanoparticles, SiO2 (hydrophilic), SiO2 (hydrophobic), ZnO and TiO2 nanoparticles on foam stability under high temperature condition, and in the presence of light crude oil were investigated. Results from this study has shown that SiO2 nanoparticles of the hydrophilic type at concentration three times lower than the surfactant concentration have significantly improved the foam half-life by 2 times longer than the surfactant alone at temperature of 110°C, in the presence of light crude oil (45° API). No improvement of foam half-life was shown by ZnO nanoparticle used in the surfactant formulation. The presence of SiO2 (hydrophilic) nanoparticles have significantly reduced the detrimental effects of light crude oil and strengthen the foam by increasing the viscosity of surfactant from 4.38 cP to 10.01 cP in the presence of 0.15 wt% SiO2 (philic) nanoparticle. The significant increment in viscosity has maintained the wetness of foam, thus reducing the rate of liquid drainage at the temperature above boiling point of water. The SiO2 (hydrophilic) nanoparticle-surfactant formulation was observed to have produced uniform sized bubbles compared to surfactant formulation alone. This indicates that nanoparticles are able to restrict shrinkage or expansion of bubble by creating a steric layer at the lamella structure which consequently restores the foam stability. The foam stability tests, determined as foam-half-life, were performed using inert nitrogen gas as the gas phase to eliminate other factors that may affect foam stability.
Floating Unit Mooring Integrity Management - Experience in the Malaysian Water
Authors: Rahman Hirzi Abd , Keresnan Hariharan , Hamid Ir. Saifulbahari Abdul
Published: March 2018

The present paper documents how best industry practice for Mooring Integrity Management (MIM) are implemented regionally in the Malaysian waters. Observations from in-situ inspection of mooring systems situated in Malaysian waters have been collated for a number of Floating Units that have different types of mooring systems: spread moorings, external turret moorings with chain table above and below the mean water line. One mooring system was recovered and brought back at the yard for detailed inspection. The observed degradation rates due to wear and corrosion has been measured. Operational feedback gathered during the offshore campaigns is also given. This information is shared with all the stakeholders involved in the MIM process to further improve their own internal procedures, in-house knowledge, tools, or decision-making criteria for best practice to continue being applied in the region.
The Feasibility Study of OTEC Integration on a Semi-Submersible O&G Production Platform
Authors: Yen K. , Jing X.
Published: March 2018

Ocean Thermal Energy Conversion (OTEC) technology uses the water temperature gradient between the cold deep ocean and the warm ocean surface to generate clean renewable power. This system requires one or several cold water pipes (CWPs) of large diameters to transport large amounts of deep-sea cold water to the floating platform topside. Until now, there is no stand-alone floating OTEC system in operation offshore, partly due to the associated high capital expenditure (CAPEX). In this study, a cost-effective approach for small-scale OTEC technology application is introduced by integrating one compact OTEC module directly onto a semi-submersible oil and gas (O&G) production platform. In addition to the mooring lines and risers, the CWPs would be attached to the columns of the semi-submersible platform in a way similar to that of vertically hanging risers. This study assesses whether installing four CWPs associated with a hypothetical 1 MWe OTEC module on a semi-submersible production platform would have any major effect on the hull global motions and the dynamic performance of the risers and moorings. The study investigates the feasibility of a small OTEC system installation on a semi-submersible platform and provides useful reference and guidance for OTEC technology applications on O&G facilities in general.

Global motions of a semi-submersible hull due to the installation of the OTEC module and CWPs are studied using nonlinear fully coupled time-domain analysis. The parameters of the CWPs which are investigated include length variation. The sensitivity of the hull motions is checked considering several design environmental conditions. The hull global motion and riser dynamic performance are analyzed using engineering analysis programs. The global motions from coupled analysis are applied to detailed Finite Element Analysis (FEA) models of the CWPs for strength checking. For large diameter CWPs, a slight discrepancy in the modeling and wave or current load calculation in the global coupled model and the CWP detailed FEA modeling could result in a significant error in the computation results. For this paper, the simultaneous approach is adopted by TechnipFMC in-house programs, i.e. coupling RodDyn with MLTSIM for global coupled motion analysis and stand-alone RodDyn for CWP FEA analysis. Identical CWP modeling is used in both coupled analysis and detailed FEA simulation.

From coupled analysis of the proposed semi-submersible system with CWPs, the effects of the CWPs are found to be significant yet not detrimental to the floating platform system performance as they could be mitigated in the design. Thus, installing a small pilot scale OTEC module on a semi-submersible production platform to generate around 1 MWe of electrical power is shown to be feasible.
Digital Twin Bridging Intelligence Among Man, Machine and Environment
Authors: Poddar Tushar
Published: March 2018

Digital transformation is increasingly getting imminent in every facet of our life and in our eco-system. Data driven Industry is becoming a house-hold word in the corporate sectors. In the low oil and gas price environment and sharp drop in the cost of installing renewable sources of energy Industry, It has become important and imperative to provide greater focus into stricter cost control in the CAPEX and OPEX of the offshore oil and gas assets/facilities joining the bandwagon of Industry – 4.0 revolution that aims to institutionalize the digital environment adopting emerging technologies such as wireless pervasive sensor, IoT, Big Data, Data Analytics, Machine Learning, Artificial intelligence etc. The Digital Twin is one such technologies that would help manning the Asset very effectively in almost all respects providing myriads of benefits. It was named one of Gartner's Top 10 Strategic Technology Trends for 2017 (Reference –1).
Drag Reduction Using Microcavity on Flat Surface
Authors: Razzak M. A. , Akter S. , Aravind B. , Hannan M. A.
Published: March 2018

This research focuses on the study of drag reduction under the application of microcavity on a 2D flat plate using Detach Eddy Simulation(DES). The study found a maximum of 39.34% reduction in shear stress for laminar flow and 35.4% for turbulent flow under the application of microcavity. A microcavity surface is usually defined as a surface textured with microscale holes. The fundamental phenomenon behind the reduction in shear stress for both laminar and turbulent flow may be comprehended to be due to the appearance of vortices inside the cavity which results in the instigation of a slip velocity at the interface of the vortices inside the cavity and the fluid flow. However, it has also been found that in comparison to smooth surface, the overall drag for the cavity surface is higher in the laminar flow regime and a maximum of 24.57% change in overall drag reduction is observed in the turbulent flow regime. The physical reason behind the appearance of a higher overall drag in the laminar flow regime could be because of the earlier appearance of flow separation. It is also observed in the turbulent flow regime, that the strength of turbulent fluctuations of the smooth surface is far stronger than that of the cavity wall thereby resulting in the reduction of shear stress, delay in the transition to turbulent flow and flow separation.
Hydrodynamic Study of Free Standing Drilling Risers under Typhoon Generated Swell
Authors: Yong H. Y. , Liew M. S. , Ovinis M. , Danyaro K. U. , Lim E. S.
Published: March 2018

A Free Standing Drilling Riser (FSDR) is a modification to drilling risers that enables rapid disconnection in an event of a typhoon. Air cans were installed to keep the drilling riser standing upright at its original location whilst the drilling rig sails away to safety. This mechanism can be used during a typhoon event as pulling back the whole riser string is a time exhaustive procedure. Typhoon occurring from distant seas can generate strong long period swell. Despite numerous studies on FSDR mechanism, the effect of typhoon generated swell on FSDR have not been reported. The objective of this paper is to study the hydrodynamic response of the FSDR mechanism under typhoon generated swell. Four sensitivity analysis based on swell height, swell period, wind wave height and wind wave period were conducted in Orcaflex10.1c finite element modelling software. The results shown that FSDR mechanism were reliable under typhoon generated swell. With the increase in swell height and swell period, the FSDR hydrodynamic response (lateral displacement, bending moment and von Mises stresses) increases. Since the disconnected FSDR was located out of the wave impact zone, increase in wind wave height and period have little to no effect on the hydrodynamic response.
Large Diameter Hybrid Bit with Sharp and Dense Inserts Drills Hard Carbonate Formations with Exceptional ROP
Authors: Bone K. , Kerimofski R. , Gauld J.
Published: March 2018

Carbonates are often drilled with aggressive drill bit features such as sharper PDC cutter chamfers and lower backrakes of the cutters. Bit aggressiveness features can produce higher penetration rates through hard carbonates, but the potential for increased wear can be detrimental over long intervals.

A field in the Timor Sea, offshore Northern Australia, has an 1800m surface hole interval where the chosen drill bit design must be capable of drilling a long carbonate section, prior to intercepting a hard, interbedded section. After this section, there is another long carbonate formation before casing point. Sustaining any slight cutter edge dulling can dramatically affect the penetration rate potential in the interbedded section, and the bit's ability to drill the post interbed section.

Hybrid technology in 17.5" hole size was recommended for this field during a 2014 drilling campaign due to its increased durability through interbeds as compared to conventional PDC technology. This durability was seen in offset fields in the region, and had resulted in performance advantages and time savings.

The new hybrid bit was used on the first well with success, drilling the interval in one run, as compared to the 2-3 bit runs seen on prior wells in the region when using conventional PDC and TCI technology. With learnings from this first well, a design change was implemented which saw the hybrid TCI cones employ a sparser wedge heel instead of ovoid heels. These modifications saw minimal change in performance on the later wells. From the 2014 campaign results, a recommendation was made to increase the insert heel aggressiveness. Development and improvement in insert carbide grades during 2015-2016 led to the capability and introduction of increased integrity and aggressiveness with conic geometry inserts introduced to hybrid TCI cutting structures. New hybrid designs with the sharper and higher density insert cutting structure were used in offset fields and showed strong performance improvements.

During the most recent 2017 drilling campaign, the sharp conics and dense insert cutting structure layout of the new Hybrid product line was applied in the Timor Sea and mirrored the performance advantages seen on offsets. A previous interval best time of 73.2hrs in 17.5" hole was reduced to just 37.7hrs with a sharp and dense hybrid design and to just 26.3 hours with a 16" hybrid utilising the new design features, reducing time taken to drill the interval by 50% and 65%.

This paper illustrates the design history, lessons learnt, and differences in insert geometry and how this contributed to the improvement in penetration rate in a challenging application.
Fatigue Evaluation of Super Duplex Stainless Steel after 17 Years of Service in a Dynamic Umbilical in the Åsgard Oil and Gas Field, Norway
Authors: Soerowidjojo Kukuh W. , Svedberg Daniel
Published: March 2018

Super duplex stainless steel tubes in grade SAF2507 have long been used for umbilical application in deep water oil and gas subsea systems. One of the oldest subsea systems installed with super duplex stainless steel tube SAF2507 is at the Åsgard oilfield located in the Norwegian Sea about 200 km offshore of the north part of Norway (figure 1). The Åsgard field comprises of the Midgard, Smørbukk and Smørbukk South deposits, which were discovered in 1981, 1984 and 1985 respectively.

Corrosion evaluation of the tubes was presented at EUROCORR 2016, Montpellier, France, September 16th 2016 by Cathrine Holager, Materials Engineer (Aker Solutions) and authored by Karin van Thoor (Aker Solutions) and Sophia Ekman (Sandvik Materials Technology R&D) with the title of "Corrosion Assessment of the 17-year old Åsgard Smørbukk Umbilical".

In addition to the previous report, this following article will report on the investigation of the fatigue properties of the tubes in two sections of the umbilical tubing installed in this field. Samples were taken from different areas of the dynamic umbilical, i.e. the splash zone and the most dynamic zone, and evaluated by fatigue testing.

High frequency fatigue tests were performed on the samples and showed that fatigue properties did not differ significantly. The tests showed insignificant reduction in the fatigue strength of the tubes used both in the most dynamic part and splash zones. In addition, mechanical properties were evaluated to understand the effect of deformation history from fabrication, service life and sample preparation. No significant effect, besides a slight hardness increase compared to the delivery condition, was observed.
Effect of the Rotary Steerable System Steering Mechanism on Wellbore Tortuosity in Horizontal Wells
Authors: Alrushud Albaraa , Mohammad Muntasar , Oliveira Victor , Zahrani Bader
Published: March 2018

This paper describes a new approach to evaluating the effectiveness of the rotary steerable system (RSS) steering mechanism on wellbore tortuosity in horizontal wells. Wellbore tortuosity in drilling applications is defined as any unwanted deviation from the planned well trajectory. As reservoir objectives become more complex and exact, operators increasingly perceive the wellbore tortuosity as a serious concern in the process of drilling, completing, and producing wells.

Strict criteria were set during the classification process; the studied wells have a common geology and trajectory, and they use a very similar bottomhole assembly (BHA) design. The inclination values from the wireline tool are used to illustrate the attainable benefits in terms of wellbore quality and measure wellbore tortuosity. In addition, the wireline inclination data are compared with the actual measurement-while-drilling (MWD) survey to highlight the existence of the micro-dogleg severity (DLS) that cannot be measured by standard surveys.

Due to the theoretical differences in the steering mechanism between the various types of RSS, it has been claimed that utilizing one steering mechanism over another can produce a less-tortuous wellbore. These steering mechanisms have previously been classified as either push-the-bit or point-the-bit mechanisms. The relative merits of a push-the-bit steering mechanism vs. a point-the-bit steering mechanism is an over-simplification; neither mechanism can deliver the premium wellbore quality the industry demands from RSS. The present study introduces the continuous proportional steering method (CPSM), and demonstrates how this mechanism can provide superior wellbore quality by reducing wellbore tortuosity. In addition, a superior inclination hold performance is observed in horizontal sections drilled with the CPSM. Curve intervals are more continuous and smoothly drilled through the planned directional changes.

The research becomes a useful reference to analyze the performance and efficiency of RSS steering mechanisms across drilling and workover operations. Directional drilling service companies are encouraged and challenged to improve the efficiency and accuracy of RSS mechanisms, improving the hole quality and reducing micro-doglegs.
4D Seismic Qualitative Interpretation for Water Injection Monitoring: Case Study in Southeast Asia
Authors: Danaei Shahram , Hermana Maman , Ghosh Deva Prasad
Published: March 2018

For many decades, Enhanced Oil Recovery (EOR) scheme has been initiated to improve recovery factor for various oil and gas fields worldwide and Malaysian basins also are no exception. Monitoring reservoir during EOR schemes has become a priority for oil and gas companies operating in Malaysian basins. Monitoring reservoir has an incontrovertible part in reservoir management and field development planning. As a monitoring technique, 4D seismic method has proven its ability to surveil primary production of the oil and gas reservoirs. This technique has also been used to monitor the reservoirs under various phases of enhanced oil recovery schemes.

4D seismic reservoir surveillance provides a sizable coverage over reservoirs which makes it possible to depict reservoir fluids movement. This advantage and also its ability to capture acoustic contrasts between various reservoir fluids have made the 4D seismic as a widespread technique for monitoring purposes. 4D seismic reservoir surveillance has been implemented for a field located in Malaysian basins. The first seismic survey has been shot in 1995 prior to production and injection activities. In 2000, production started from reservoir I-X in the field and water injection scheme also commenced exactly in the same year. Field asset team including geoscientists and engineers faced with early water production for a producer well; therefore, they decided to run another seismic survey in 2006.

Time-lapse seismic data analysis has been performed based on the qualitative interpretation of 4D seismic data. The analysis has been done separately for both seismic surveys and also on seismic differences of monitor minus the baseline. This analysis has been done on amplitude for both seismic surveys and also on 4D amplitude values. In addition, 4D seismic attributes have been used to monitor the reservoir and depict the movement of injected water. 4D Phase shift (−90°), and 4D acoustic inversion complement the injected water monitoring.

The results for various time-lapse seismic attributes are similar which indicate the expansion of injected water from injector wells after six years of aggressive water injection scheme. This expansion seems almost uniform for the five downdip injector wells; however, uneven pattern in water distribution for updip injector well proves the inefficient oil sweep for that region. Remaining oil area has been determined based on the analysis of 4D seismic attributes. The early water breakthrough for a producer well has been contributed to a channel between the well pairs (Injector and producer).
Application of Neural Network in Formation Failure Model to Predict Sand Production
Authors: Ketmalee T. , Bandyopadhyay P.
Published: March 2018

Sand management is one of the key component of Bongkot production processes. Current sand production prediction is based on a model which requires sonic and density logs for all the wells. However, a combination of complex well architecture and focus on reducing well cost resulted in many wells not having acquired these important logs. This project has implemented new technique of "Artificial Neural Network" to solve this problem. Using this method, synthetic logs are generated to obtain the values of missing sonic and density data. These data are then used in the existing sand models to predict sand production potential.

This project was evaluated with three field cases. The sand failure predictions based on synthetic rock properties matched with actual sand production. Therefore, the sand prediction workflow has been updated to include log synthetic if acroustic or density log are missing.
Wind Turbine Hybrid - Future Small Power Generation for Small Field
Authors: Hamdan Ir M Faizal , Yasir Ir M Faudzi , Kamal Ir A Fadzil M
Published: March 2018

Geographic location provides an advantage on solar, however the climate effects the efficiency of solar across one year. Monsoon session of average 3 – 4 months in a year, with heavy rain through out Sept till Dec continue to 1 – 2 months early of the years, effect the efficiency of PV system. However, within this season, it is observed that wind has a potential as energy source for wind turbine. Prove ofconcept provide some promising early data of potential utilization of wind turbine.

Solar energy and wind data gathering is crucial to size the maximum potential generation of alternative anergy. Based on the meteorological data, Malaysia wind record in average of 3m/swhichis near to impossible to generate wind energy. Turbine technology advancement exploit into smallpower machine generating power at minimum wind speed, producing power in the range of 3 – 5 kW. While solar identified and static technology, hybrid with wind would be the best solutions to overcome climatic change at offshore.

POC data indicates solar-wind energy generation ratio would be at70:30. However, special circuit system to hybrid solar and wind shall be developed and the initial design has been proven for hybrid system. Based on optimum generation system hybrid power wind solar would provides the generation capacity in the range of 3 – 6 kW, suitable and sufficient for typical small field development. The load enough to supply to instrument SCADA and field instrument system and communication. Proven system currently can be replicated to other selected small field development.

The wind turbine solar hybrid provides alternative generation which currently install in small field such TEG or Micro-turbine or CCVT. Combining both static technology and rotating machine provide high efficiency and reliable green technology for small filed development.
Applications of a Multizone Single-Trip Gravel-Pack System in Developing a Shallow-Gas Field, Indonesia: Case History
Authors: Muryanto B. H. , Fransiskus W. , Wijaya R. , Styward B. , Ji Y. , Albertson E. , Sudirgo A. W. , Hutahaean A. , Widyastuti A.
Published: March 2018

Multizone single-trip gravel-pack (MZ-STGP) completion systems not only save rig time to complete wells with long multilayer intervals but can significantly reduce capital and operational expenditures by standardizing completion design and simplifying operation complexity. It can also help improve quality, health, safety, and environment (QHSE) performance for a long-term project development.

This paper discusses a case history of an operator in Indonesia developing a major offshore field primarily with MZ-STGP completion systems to produce marginal reservoirs. A MZ-STGP system was selected to reduce multizone gravel-packing operation time as compared to conventional stacked-pack systems. The main focus was to standardize completion design and help improve system reliability and operational efficiency, which is associated with both logistic preparation and field execution. Despite exploring cost-effective solutions, operational safety—including well control, particularly for developing a shallow-gas field—was the number one priority, as usual. A new concept type of safe running system was developed and implemented as part of a field operation standard to help ensure a safe and efficient operation.

Based on MZ-STGP system trial results and lessons learned during the early stage, a standard MZ-STGP completion instruction was approved and applied as a guideline to standardize completion operation and identify and mitigate potential operational risks quickly to improve safety, performance, and efficiency. By understanding the principle of MZ-STGP system limitations, the system-working envelope was expanded and refined without jeopardizing system reliability and performance.

With more than 170 wells with MZ-STGP installation and more than 650 zones gravel packed in a 12-year time span, a case history review provides an opportunity to share lessons learned and fundamental success factors and explore the future of this technology.
Deepwater Extended Reach Well Planning through Depleted Reservoirs
Authors: Shi Beng-Hooi , Koh Jennifer , Liew Dexter , Chio Guat-Lee
Published: March 2018

The field is operated by Shell Malaysia and is the company's first deepwater asset in Malaysia. The first phase development was delivered by 2014. The planned Phase 2 campaign aims to maintain the oil production plateau. One of the campaign objectives is to produce from the deepest untapped reservoir. However, due to the depleted nature of all 3 reservoirs located above the untapped reservoir, there is a need to drill through these depleted intervals with extremely narrow drilling margin window (less than 0.5 ppg). An added complexity is the location of the reservoir which is situated directly below the hydrates bulge of the field. Due to hyrdrates disassociation concerns by producing through the hyrdate layer, the current surface location of the well is situated 3km away from the reservoir adding ERD drilling challenges to an already complex well. Lastly, geomechanical analysis indicate that the relatively high mud weight required to maintain borehole stability in the shale intervals results in a negative margin scenario between the Stabor mudweight and the fracture gradient.

To address the challenges of this well, an integrated approach between various disciplines such as Wells, Subsurface, Well, Reservois and Facilities Management (WRFM), and Subsea is a critical success factor. Every discipline plays an integral role to increase the probability of success. Some of the project enablers ongoing efforts include:

Geomechanic assessment on representative fracture gradient with lower depletion constant to widen the drilling window, leveraging the learning from UK and Gulf of Mexico (GOM) experience and borehole stability subject matter expert (SME) network.

Wells assessment on technologies in Managed Pressure Drilling and stress caging with optimisation in well trajectory and casing design.

Collaboration between Subsea, Subsurface and Wells on geohazard assessment to move subsea top-hole location to avoid potential geohazards that adds complexity to the well.

The project is going through the detailed design phase until the end of 2018. The results of the Detailed design phase will be shared during the conference.
Alternative Fiber Optic Post-Installation by ROV on Fixed Platform Jacket Leg
Authors: Danthainum Athip , Chattratichart Tanasit , Katanyoowongcharoen Somkiat , Kongchang Adisak , Thavornsuk Thasaphich , Sriparagul Jirapol , Kosanunt Pong
Published: March 2018

Nowadays, there are many fixed platforms installed offshore without fiber optic cable planned. The communication is via satellite where efficiency is limited and does not satisfy modern data management technology i.e. online monitoring system. Upgrading the communication system, Fiber optic cable is required andcan be installed by pulling through pre-install tube provided on the platform. However, not many platforms installed in 19th century came with pre-install utility tube (J-tube or I-tube). Post-install tube attached to the platform is conventional method but it involves with many offshore resources and man-power for the installation such as barge with high-boom crane, support vessels, saturation diving support vessel, etc.,consequently high costcannot avoid. Another alternative installation method to install fiber optic cable only by Remotely Operated Vehicle (ROV) was developed for effective cost reduction.

This paper presents an alternative to replace conventional approach where J-tube of I-tube is conventionally installed to provide support to fiber optic cable installed on fixed platform structure. The paper provides innovative knowledge how to develop the ROV friendly tools from design to offshore installation.
Assess Late Syn-Rift Plays in Cuu Long Basin, Offshore Vietnam
Authors: Dinh Chuc Nguyen , Nhu Huy Tran , Thanh Ha Mai , Viet Bach Hoang , Dinh Chuc Nguyen , Van Xuan Tran , Thanh Tan Mai
Published: March 2018

Cuu Long basin is a Cenozoic rift basin located in the southeastern shelf of S.R. Vietnam, containing vast potential oil and gas resources. The basin was impacted by three main tectonic periods of pre-rift, syn-rift and post-rift tectonism. Major petroleum plays in Cuu Long basin are the Pre-Cenozoic fractured basement, Oligocene and lower Miocene sandstone reservoirs. Upper Oligocene sediments were deposited during late syn-rift phase of Cuu Long basin. The reservoirs in these strata (Oligocene C and D) were previously discovered in the center, southwestern and southeastern margins of Cuu Long basin with limited total reserves, up to 5%, of Cuu Long basin's discovered reserves. Recent exploration and appraisal results of St, Tg, Rg, Ct etc. show a greater potential of upper Oligocene reservoirs with a greater variety of trap types in many areas of Cuu Long basin than that of previous assessments. Therefore, additional studies and assessments of recently discovered trap types need to be carried out for the Cuu Long basin exploration and appraisal program. This article discusses the assessments of upper Oligocene trap types and identifications of several trap mechanisms utilizing the integration of exploration methods. The research results permit better understanding of the trapping mechanisms and possible distributions of various trap types in the upper Oligocene strata of the Cuu Long basin, thus leading to better planning of exploration/appraisal strategies in the basin.
Alternative Energy Generation for Offshore Rig Power Requirements
Authors: Singh Shaurya Pratap , Singh Tamanjot , Kunal Vishal
Published: March 2018

Hydrocarbons are the major source of energy. Its increasing demand has made the hydrocarbon exploration go beyond the shore. Offshore Rig power requirements are higher compared to onshore rigs. Diesel Generators are conventionally used for the power requirements of offshore rigs. This paper aims to suggest an idea to use the renewable sources of energy (mainly tidal energy) for energy generation in offshore.

The idea is to have a Hybrid energy system, in which both the renewable and non-renewable sources of energy can co-exist together in a symbiotic relationship. The energy harnessed from tidal-waves shall be used to meet the power requirements of offshore rig alongside the diesel generator. This would result in overall more efficient and cost effective energy generation. Wave energy would be harnessed on wave energy harvester system platforms installed around the offshore rig set-up; on which the motion of floats would be transferred via hydraulics into rotation of generator which will produce electricity. The energy generated would be transferred to rig via wires and can be stored in batteries for transportation to land to meet other power requirements.

An analysis of tides/waves generation is detailed. Available data for prototype of Wave Star Energy harvester is examined followed by Monetary-Energy Capacity analysis. SWOT analysis and environmental impacts are discussed. Various parameters affecting the Tidal energy generation are scrutinized. There is a need of an alternative source of energy in offshore rigs because of high environmental impact of diesel generators and other problems associated with it.

Given the current global scenario and advancements in Electric automobile market, there is an exigency for a Hybrid energy system to meet the upcoming energy needs and boost the Global Energy Infra.