bluuebunny/crossref_metadata_2025 huggingface dataset:
A Pragmatic Approach to Enhanced Performance of Slim Mono-bore Wells
Authors: Lam Fei Shiong
Published: May 2016

Continuous development and refinement of e-line based well intervention methods help push the performance envelope and expand the possibilities for optimizing reservoir drainage. The light and agile approach increasingly adds a new dimension to reservoir management as well intervention becomes viable. In general the resources required to perform production enhancing well intervention have been reduced, which again has a direct impact on the potential revenue.

This is exemplified by a Malaysian well where build-up of scale almost ceased production. Opening the wellbore by milling out part of the accumulated scale immediately increased the production by 50%, 14 hours after the intervention operation was initiated.

This, and similar cases are addressed by the paper with a particular emphasis on the practical aspects of lightweight well intervention utilizing e-line conveyed tools in relation to slim and/or mono-bore wells as commonly found in Asia.

One other case is the successful recompletion of a mono-bore water injector done purely on e-line by way of setting a plug to isolate an existing perforation interval and re-perforate higher up in the well. Significant increase in reservoir ultimate recovery as well as oil gain over the following years of production from the H sand was realized.

Another example is the recovery of 350 liters of muddy sand from an onshore gas well thru a 3-1/2" tubing in Indonesia using e-line downhole tools.

Technology Description

Wireline Tractor

Wireline tractor technology was first introduced in 1994 (Hallundbaek, J., 1994), and the technology was primarily used for conveyance of diagnostic logging tools. However, as it achieved a reliable track record, it began to form part of many oil companies' standard solutions.

The wireline tractor (Figure 1) functions with an electric/hydraulic power relationship. The control panels, communications and internal power source are electric, while the remaining parts and functions are hydraulic. When activated, the wheels are hydraulically deployed out of the tool body and automatically start to rotate. Each wheel contains its own independent hydraulic motor, which facilitates the forward motion in the well. The tool centralizes itself in the well bore once contact with casing has been established and the cumulative traction force between the wheels and the casing wall then deploys the intervention tools into the well bore, taking the string beyond its original hang up point. Horizontally, the wireline tractor can pull a wireline beyond 9,800ft into the well bore and more than 25,000ft into a highly deviated well in addition to pushing other down hole tools (Hallundbaek, J., 1994). When target depth has been reached, the tool is powered down. The passive and immediate fail-safe feature ensures that the wheels are retracted automatically when it is powered down or disconnected.
Fiber Optic Technology for Reservoir Surveillance
Authors: Koelman Johannes V. Vianney , Lopez Jorge L. , Potters Hans
Published: May 2016

Fiber-optic sensing technology for in-well applications has traditionally focused on temperature profiling. This has limited the application of fiber-optic reservoir surveillance to recovery processes with a pronounced thermal signature. Currently, novel fiber-optic technologies entering the market promise a much wider range of subsurface measurements. This opens new avenues in well and reservoir management and highlights the opportunity for fiber-optics to become a pervasive oilfield technology. In this paper we discuss field trials that combine Distributed Temperature Sensing (DTS), Distributed Strain Sensing (DSS) and Distributed Acoustic Sensing (DAS). These trials demonstrate the potential of fiber-optic sensing technology for well integrity monitoring, gas lift optimization, in-flow profiling and downhole seismic acquisition.

Esential to realizing this potential is the development of cost-effective, easy-to-deploy fiber-optic cables optimized for these various fiber-optic measurements. We also highlight the business integration challenge of handling, storing, and interpreting data volumes that in some applications reaches levels of 1 TB/well/day. We conclude that while significant technology challenges remain, with a broad cross section of oilfield technology providers working on derisking fiber-optic sensing technologies, the industry is on the verge of a step change in well and reservoir monitoring capability.

Introduction

Its passive nature and inherent long-term reliability, combined with the ability to string together numerous individual sensing elements in a single fiber, makes fiber-optic technology ideally suited for distributed sensing in harsh and remote environments. Despite this compelling proposition, for many years this technology was synonymous with temperature sensing and thereby limited to the monitoring of well operations and recovery processes with a pronounced thermal signature. In recent years, this situation has started to change rapidly. A variety of fiber-optic sensors developed in the aerospace and defense industries are finding their way into the oil and gas industry. As multiple fibers, each providing a specific distributed measurement, can be bundled in a single downhole-deployable cable, the industry is facing a unique opportunity for robust well and reservoir surveillance based on an abundance of measurements continuous in time during the well's productive life and continuous along its well path.
Enhancing Recovery in High Salinity Oil Reservoirs through Optimized Polymer Flood
Authors: Algharaib Meshal Kh , Alajmi Abdullah Fahad Faleh , Gharbi Ridha
Published: May 2016

The applications of Enhanced Oil Recovery (EOR) techniques are encouraged by the growing demand for oil. Optimizing oil production from current resources is becoming the main strategy for many oil producing companies around the world. Among EOR processes, polymer flooding is an attractive option in many reservoirs. The objective of polymer flooding is to control water mobility inside the reservoir to favor higher oil recovery. Several design parameters are critical for the success of polymer flooding applications. The salinity of formation water is one of the challenges which impose a limitation on polymer flood applicability. In Kuwait, most of oil reservoirs are high water salinity reservoirs. Therefore, improving the performance of polymer floods under high water salinity conditions may unlock these resources which can have enormous positive effects on oil reserves. One way for this improvement is to condition these reservoirs by injecting a slug of water (preflush), ahead of polymer, with specific characteristics. In this work, lab experiments were conducted in which the effects of several design parameters of polymer flooding are investigated under high water salinity conditions. Design parameters include preflush salinity, preflush viscosity and preflush slug size. The results suggest these parameters correlate differently with oil recovery factor.

Introduction

With the current growing demand for oil led by major energy consuming countries such as China and India, securing new oil resources is a critical challenge for the oil industry. Adding new oil reserves can be achieved by finding new discoveries or by optimizing oil production from current resources. The cost associated with the first option is significant since the new resources are expected to occur in challenging environments such as deep formations or deep water. Therefore, the need to optimize oil production from current resources through Enhanced Oil Recovery (EOR) techniques is a main strategy for many oil producers. EOR processes are generally classified as thermal, miscible, or chemical processes. Reservoir's rock and fluid properties and economics dictate the choice of which EOR process to follow. Thermal methods are mainly used in heavy oil reservoirs; whereas miscible processes are suitable for lower viscosity oils. Chemical EOR processes are used to reduce reservoir forces responsible for oil entrapment. There are different versions of chemical processes depending on the type of fluid used such as: polymer, alkaline, and surfactant.
Rock Type Classification and Saturation Modeling in a Heterogeneous Low-Permeability Reservoir from Offshore India
Authors: Agarwal Gunja , Sagar Rajiv , Behera Bijay
Published: May 2016

In any reservoir modeling exercise, accurate estimation of initial water saturation is crucial to determine the in-place hydrocarbon volumes. The water saturation in a reservoir is a function of the reservoir rock quality and the capillary forces present.

Pore throat size distribution and rock quality strongly influence the amount of capillary-bounded water and mobile water in the reservoir rock. A good understanding and proper classification of rock types based on reservoir quality is essential for reservoir property population. Also, in absence of the core data, the practice of using single-well models and well logs to identify capillary pressure curves and hence water saturation distribution is not ideal for a vast heterogeneous reservoir with many wells.

A case study is presented in which extensive core data, in particular RCA and SCAL results, are analyzed. These results are integrated with petrophysical interpretation to identify different classes of sand units based on the reservoir rock quality and amount of clay present. It is uniquely noted in this work that volume of clay, Vclay, was a better basis for rock classification in this reservoir.

A numerical method is used to unify and integrate SCAL data acquired over a 1000-m section of the reservoir in more than 10 drilled wells. Parameterized equations are derived to populate initial water saturation in the static or dynamic model. The water saturations obtained from these parametric equations are subsequently validated with the well log saturations and vice versa. These results are further validated by history matching the drillstem test result, showing excellent results.
Indonesia "Tunu 18 days" Project Case History: Innovations and New Technologies Bringing the Well Construction Performance to Unthinkable Levels
Authors: Oumer Samir , Widiwibowo Fajarianto , Yunus Fata , Choux Jean-Claude
Published: May 2016

Tunu is a giant gas field discovered in 1977 and located in the Indonesian Mahakam delta, East Kalimantan. To support the field development maintaining a high gas production level, more than 750 wells have been drilled and completed. Late 2010, Tunu field cumulative production was over 7.5 Tcf gas.

Five rigs are continuously drilling in the swamp area to deliver around 100 wells per year highlighting the stakes associated to the well construction optimization. Since the 80's and the early beginning of the drilling operations on Tunu, a tremendous work has been done to 1) reduce the overall well construction duration, 2) reduce the well equipment costs without jeopardizing the operations safety and the wells productivity. The first important leverage was the implementation of innovative well architectures in order to construct "fit for purpose" wells strictly answering to the subsurface formation characteristics avoiding any over design. The evolution of the technology has been fully utilized and wisely implemented in order to improve the performance of our drilling and completion operations. A huge effort has been delivered to minimize the costs associated to the equipment design and material selection. Finally, a shared performance culture has been successfully implemented on our operations to systematically challenge ourselves outside of our comfort zone: the "Industrialization" of the well construction process is now developed.

The Tunu wells targeting the "main zone" reservoirs have seen their average duration reduced by 70%!!! From a well duration of 55 days in the early 80's, the drilling and completion teams managed to reduce it down to 17 days in 2011.

This performance level has been reached over 30 years of thorough improvement process follow-up. A joint effort of all involved entities as geosciences, marine, logistics, planning, service companies and well teams made this achievement possible.

In 2011, two innovative well architectures have been implemented on Tunu and field trials are planned for two new technologies. The continuous improvement process is not closed yet: "Tunu 15 days" on its way to become a reality?
The North Malay Basin: Analog for the Reservoir Distribution of the Triassic Rift Basins, Northeastern Thailand
Authors: Pongpisuttinan Teerapong , Anis Ahmad , Ponthanom Piyanuch
Published: May 2016

This reference is for an abstract only. A full paper was not submitted for this conference.

The North Malay Basin is an intra-cratonic basin formed by rifting in early Tertiary time. North-South (N-S) and Northwest-Southeast (NW-SE) oriented normal faults form a series of asymmetric half grabens. Some of these have shown the best imaged seismically. Combined with a number of wells that penetrated the synrift section in this and adjacent half-grabens, leads us to a clear picture of the overall geometry and reservoir distribution of the basins. In attempt to understand more about the nature and type of reservoirs encountered in the North Malay Basin, Na Phor Song, the Triassic Rift Basin located in northeastern part of Thailand was selected to conduct geological field survey. The outcrop exposures of this basin and subsurface data from the North Malay Basin were studied and compared, resulting in the definition of 8 synrift sedimentary facies: Alluvial Facies, Fluvial Facies, Proximal Delta Facies, Shoreface Facies, Lacustrine Swamp Facies, Distal Delta Facies, Deep Lacustrine Facies and Fan Delta Facies.

The same facies observed in the outcrops can be interpreted from well control and seismic sequence analysis in the half graben, North Malay Basin. The areal distribution of the seismic facies can provide important insights to understanding the overall geometry of the Triassic Rift Basins. The facies successions observed in outcrop in the Triassic Rift Basins provides the means to better understand and define synrift reservoir fairways in the North Maly Basin. The seismic and well facies evaluation conducted in the exploration program for the North Malay Basin can provide insights to better understanding the reservoir distribution in the Triassic Rift Basins. Together, they can provide the means to improve the prediction of reservoir and source-prone facies other rift basins in the Gulf of Thailand.
Electromagnetic Casing Inspection Tool for Corrosion Evaluation
Authors: Brill Thilo Michael , Demichel Cindy , Nichols Edward Andrew , Zapata Bermudez Fernando
Published: May 2016

Pipe corrosion is a natural phenomenon in the harsh environment of oil and gas production wells, costing billions of dollars each year. Monitoring such corrosion allows for timely mitigation to prevent leaks, environmental damage, or catastrophic failures.

Corrosion of pipes is inferred from measurement of internal diameter and wall thickness. Mechanical finger calipers provide a high-resolution image of the internal pipe surface. Ultrasonic tools measure both the internal diameter and thickness of a single pipe, providing the pipe is filled with a fluid. Production tubing is a barrier to caliper, ultrasonic, and flux-leakage electromagnetic tools, preventing the assessment of outer casings. Remote-Field Eddy-Current (RFEC) tools respond to the total metal thickness of all the combined casings. The measurement is valid in single and multiple casing strings and is largely insensitive to the kind of material filling the pipe.

This paper presents a new slim electromagnetic (EM) imaging tool enabling casing assessment without removing the production tubing. The tool excites eddy-currents in the tubulars using a powerful low-frequency solenoidal transmitter. Distribution and strength of the eddy-currents depend on the geometric properties of the casings, their EM properties, and the presence of defects. The tool operates in the RFEC regime using large transmitter-receiver spacings, in which the measurements directly determine the total metal thickness. Mandrel-mounted coils provide the average total metal thickness, and eighteen small pad sensors around the tool provide an image of local pipe wall metal loss.

The combination of low- and high-frequency images, together with the average total metal thickness, provides a quantitative, high-resolution assessment of pipe condition. Log examples show detection of casing joints, additional casings strings, and presence of corrosion damage in the low- and high-frequency images.

Introduction

Corrosion is a relentless process with electrochemical, chemical or mechanical origins that is difficult to slow down: it is a 'silent killer' (Acuña 2010). In the oil and gas industry corrosion monitoring is used to assess the well condition as a basis for planning intervention and mitigation strategies. Among all the high-technology systems and equipment that are installed in oil and gas production wells, the corrosion of well casings causes the most problems. Apparently stable casing can suddenly develop a leak that may be the first evidence of a severely corroded section that left untreated may force abandonment of the well in the near future.
Performance Evaluation in Data Rich Fayetteville Shale Gas Plays - Integrating Physics-based Reservoir Simulations with Data Driven Approaches for Uncertainty Reduction
Authors: Xiao Yitian , Van Den Bosch Rainer H. , Liu Faye , Steffen Kurt
Published: May 2016

This joint study combines physics-based reservoir simulations with automated screening including data mining and pattern recognition to evaluate the key controls on shale gas performance in Fayetteville, USA based on publicly available data comprising approximately 2000 wells.

For data screening automated tools were developed to efficiently process large and rapidly growing data volumes. Workflows include probabilistic prediction of Estimated Ultimate Recovery (EUR) from decline curve analysis, diagnostic mapping, and multi-variate cross correlations. Key data utilized were gas production, well location, reservoir depth, well design and completion detail.

Numerical simulations were conducted on 6 selected wells with 2.5 - 3.5 years of production data for history matching, model calibration and sensitivity tests. The models comprise a dual-porosity, dual-permeability approach incorporating multistage hydraulic fractures, Darcy's flow, diffusion and gas adsorption/desorption to predict gas rate and EUR.

Key results include:• Average EUR per well has increased more than 5 fold from 2005 to 2009 suggesting a steep learning curve in identification of sweet spots coupled with improved well drilling and completion techniques.• Top performing wells completed since 2009 have an average completion length of ~4,100 ft and comprise 12–13 stimulation stages. However, longer wells, more completion stages and more proppant volumes do not always lead to higher well performance.• High performance wells are concentrated in two areas, providing evidence for geological control, although the performance (dynamic) sweet spots do not necessarily correlate with the resource density (static) sweet spots.• Despite improved drilling and completion techniques and improved subsurface illumination through 3D seismic and micro seismic, a significant number of completed wells still fall in low tier performance categories.• The reservoir simulation models require either the presence of natural fractures or higher matrix permeability (~several uD) in addition to hydraulic fractures and conventionally measured matrix permeability (~10s - 100s nD) to match production history.• Matrix permeability in the range of 10s to 100s nD appears to have limited impact on gas rate in the presence of natural fractures.• Gas desorption can contribute up to ~30% of gas production; desorption occurs early and increases with time.• Modeling results suggest an effective drainage area and an optimal well spacing of ~ 60 acres with current stimulation practices.• EUR predictions from reservoir simulations and automated decline curve analysis yield consistent results given the uncertainties from limited production data.
Novel Reciprocating Submersible Pumping Technology for Performance Improvements in Oil Production
Authors: Wang Zhigang
Published: May 2016

Submersible pumping technique with linear motor is crucial for oil production in low permeability reservoir, especially in China and South East Asia. However, how to improve the life, reliability and performance of the submersible linear motor and cut energy consumption is still a challenge for oil production engineers. To solve these issues, several novel designs on lubrication, hydraulic buffer, floating suction device and automatic motor driven and control methodologies are proposed.

The impact of these designs on performance improvements, computer work and field test results are analyzed in this paper.

The technology presented is convenient to implement, which can adapt to low production well, directional well and horizontal well to overcome local permeability reduction.

A large scale field application test was carried out and satisfactory results were achieved. The motor life was doubled, maintenance cost was greatly reduced and oil production was significantly increased. The power consumption was 40% less than conventional techniques.

The key contributions of the technology proposed are: First, a new motor driven method applied to directly connect pump plunger with motor mover greatly improves the pumper lifting force and reliability; Second, a full set of lubrication device is designed that involves an automatic pressure regulator, an unique spiral channel and the automatic valve control technology, which improves not only the motor lubrication but also the motor cooling; Third, an advanced hydraulic buffer device located at the lower end of the stator is designed to prevent shock and collision damage to the motor; a floating suction device is designed to prevent the deposition of sand and impurities into the motor and oil; Fourth, an automatic control of start-stop motor technology is developed to allow the motor automatic start-stop on variation of liquid level, preventing the motor no-load and increasing motor life to achieve the energy saving requirements. The structural application of these techniques has proven useful to improve the reliability, service life of the motor and reduce the energy consumption as well as maintenance costs. In addition, these techniques also contribute to partially arresting the declining production trend and more importantly improve oil recovery.
The Evolution of the Drill String Design on Sour Field (Puguang) to Improve Performance and Safety Margins in Sour Environments
Authors: Flores Vincent Pierre , El Bachiri Kamal , Fei Li , LI Yumin , Zhang Da
Published: May 2016

Puguang region is known for containing sour fields with significant amount of H2S. Since 1975, sour service wells have been drilled entailing critical drilling conditions. To optimize drilling efficiency without sacrificing security, drill string improvements have been always looked for, by carefully evaluating steel grades, drill pipe sizes and connections.

The evolution of drilling programs has driven the industry to develop more suitable solutions adapted to extreme and aggressive conditions such as Sour Service environments. High strength drill pipe is often necessary to achieve deeper drilling performance, even when Sulfide Stress Cracking susceptibility is observed in minimal concentrations of H2S in partial pressures. Due to the astringency of the sour environment, particular precautions have to be defined to select and characterize an adapted Sour Service steel grade.

This paper presents the evolution of choices in drill string design from basic API grades and connections to adapt and proprietary steel grades resistant to H2S with a high mechanical performance properties and high torque double shoulder connections.
Beam Pump - Installation without workover Technique
Authors: Nadoon Apiwat , Toempromaraj Wararrit , Sompopsart Suwin , Prayadsup Amnuay , Suwanmisara Adisak
Published: May 2016

In the Sirikit Oil Field (S1), a number of artificial lift techniques (ESP, PCP, GL, Beam Pump etc.) have been implemented to assist the depleted oil producers to flow the well fluid from underground to surface. The type of artificial lift in particular well is considered depended on the well conditions.

The gaslift is the main artificial lift which being typically used in the Sirikit oil field (S1). It is the technique that covers the wide range of well conditions. However in the well which has low reservoir pressure such as below 500–600 psi, the gaslift technique seems to be low efficient and not suitable for this well condition. Therefore the other artificial lifts are considered, and the beam pump is one which is more suitable than the gaslift. Because the most benefit of beam pump can effectively produce the oil when the reservoir pressure is very low such as 100 psi but the gaslift is unable to do.

Generally gaslift and beam pump artificial lifts selection will depend on the well conditions. In areas where the Water flood Project is planning in the future, the well conditions will be changed from the low pressure (depleted reservoir) to high pressure. The waterflood project will require the plenty of time on reservoir simulation, study work and the project implementation. The sub-surface and surface engineering to prepare the surface facilities and well completion for the waterflood project will take few more years and consequently resulted in oil deferments or oil leaving underground.

Since the challenges on well conditions to make a good business in short term winning on quick oil production meanwhile keeping a good on long-term oil recovery from waterflood project. The HYBRID completion of beam pump and gaslift is then invented, since the reservoir pressure response is the key driver for the artificial lift design. The depleted or low reservoir pressure is good for a beam pump technique however once the waterflood project implemented and the reservoir pressure get responded and be higher and higher, then the beam pump technique will idle the oil production and push to the limit by the downhole pump's capacity. The gaslift then will be suitable after the reservoir pressure's response however recompletion the well by the work-over will cost about 150–200 K USD so it would be better if we can provide the HYBRID artificial lift to the well since the beginning.
Enhancement of IFT Reduction in Surfactant Flooding by Branched Alcohols
Authors: Awang Mariyamni Bt , Dzulkarnani Iskander B. , Wahyudeen B. Zakaria Mohamed
Published: May 2016

Published research showed that alcohols are able to reduce the interfacial tension (IFT) between surfactant and oil when added even in small amounts. Much of the work had focused on primary alcohols. This paper presents our preliminary investigation on the effects of branched alcohols on interfacial tension changes in crude oil- sodium dodecyl sulphate mixtures. Branched alcohols are chosen because many forms of bio-waste contain a significant number of branched components and a cheaper product is expected if the natural structure of the feedstock can be exploited. Our results show that 0.5 wt% of branched alcohols result in similar amount of reduction caused by 1 wt% of sodium hydroxide. Sodium carbonate gives better performance than sodium hydroxide or the branched alcohols used, however its use is limited to low salinity conditions. More studies will be conducted with an emphasis on the effects of branching, solvation ratio and salinity.

Introduction

Chemical flooding is limited largely by the cost of chemicals such surfactants. However, literature has shown that several additives such as alcohols are able to further reduce the interfacial tension (IFT) between surfactant and oil when added even in small amounts. Consequently, the chemical cost is reduced by using a lower concentration of surfactant. Branched alcohols are chosen because many forms of bio-waste contain a significant number of branched components. A cheaper product is expected if the natural structure of the feedstock can be exploited in the production reactions. The oil palm industry in Malaysia generates a large amount of waste and a newly introduced crop, Jatropha oil is a potential feedstock. Alcohols such as ethanol and propanol have been used as additives in surfactant flooding. However, not much work has been conducted on branched alcohols. Interfacial tension directly affects the microscopic displacement efficiency in surfactant flooding and therefore, a low IFT system indicates good microscopic efficiency can be achieved. This ongoing research investigates interfacial tension change in a surfactant/crude oil system using branched alcohols as additives.
Experimental Investigation of Salt Precipitation during Gas Injection into a Depleted Gas Reservoir
Authors: Golghanddashti Hassan , Saadat Mohammad , Abbasi Saeed , Shahrabadi Abbas
Published: May 2016

Water vaporization and its induced damage around the wellbore are important issues with a wide application. This phenomenon could be observed wherever dry gas is injected into gas and oil reservoirs in presence of connate water. Gas injection for EOR, pressure maintenance or storage purposes and carbon dioxide sequestrations in aquifers are examples where it could happen. There are two counteracting factors existing in vaporization phenomenon, water saturation decrease and induced permeability impairment by salt precipitation in the porous medium. Water saturation decrease tends to raise injectivity or productivity by providing higher share of passage to gas. Salt precipitation tends to reduce them by the damages induced. The interaction of these two factors determines how productivity or injectivity will alter. It is a quite new subject finding its interest in application however limited researches are done on this up to now and many aspects are left unknown.

We conducted an experiment to investigate the impact of water vaporization on injectivity for core samples of an Iranian gas reservoir candidate for gas storage. According the results, the medium with higher permeability experiences an improved injectivity during gas injection while the medium with lower permeability experiencing an impaired injectivity. Now distribution of each medium around the wellbore dictates if a field application would face injectivity increase or decrease.

Finally, the interaction of two effective factors mentioned above differs for each porous medium and water system. Therefore, an experimental investigation for each system should be performed in lack of a general formulation for injectivity or productivity alteration because of water vaporization around the wellbore.
Well Integrity remediation - A Challenge for Swellable Technology
Authors: Durongwattana Nithipoom , Toempromraj Wararit , Jedsadawaranon Panit , Sompopsart Suwin
Published: May 2016

The word "integrity", is defined as: "the state of being whole, complete and entire, in an undiminished or unbroken condition". Well Integrity Remediation, therefore, is maintenance of well quality to insure such totality and undiminished condition.

Well integrity has received a significant attention these days, from well conception to well abandonment. The driving factors such as the high oil price along with new techniques for Enhanced Oil Recovery (EOR) make it feasible and profitable to prolong the field life beyond original design. However, an extended well life has led to a higher probability of well integrity related problems e.g. Fatigue, Erosion and Corrosion.

As case in point, PTTEP S1 - Sirikit Oilfield, experiences unavoidable well integrity problems, primarily relating to corroded casing due to water encroachment. In this respect, it is the sub-surface challenge to minimize the shut-in time and prolong overall well life. To address these problems, swelling elastomer was considered for a remediation work by isolating leak casing from production system, and thereby preventing further well integrity failure. Properties of inherent elastomeric substances is designed such that, when in contact with the wellbore fluid, will react and swell against the contacted surface providing long-term isolation with no mechanical intervention. The known product e.g. Swellable Packer has been proven for many years mainly for open-hole applications, until such a time as cased-hole remediation techniques are implemented by PTTEP.

This paper examines case histories and demonstrates the practicality of Swellable Packer in the cased hole application which aging casings wall were chronically corroded by water encroachment. Two different types of wells: producer and injector, which casing confirmed failure by Production Logging tool (PLT) and Ultra Sonic Imager tool (USIT), were selected as candidates. The background, operation sequence and performance evaluation methodology are detailed on the following sections in this paper.
Pilot Plant Test of a New Syngas Production Process for Floating GTL to Utilize Associated Gas
Authors: Suehiro Yoshifumi , Watanabe Yoshiyuki , Kawasaki Tsutomu , Yokoyama Kota , Ikeda Koichiro , Masuda Masataka
Published: May 2016

This reference is for an abstract only. A full paper was not submitted for this conference.

JGC Corporation, Osaka Gas Co., Ltd and Japan Oil, Gas and Metals National Corporation (JOGMEC) have been jointly developed a new syngas production process, Advanced Auto-Thermal Gasification (AATG) process, consisting of a new auto-thermal reforming catalyst with high-performance desulfurization of natural gas.

This paper includes the result and discussion of the applicability of AATG process for Floating GTL (FGTL). For application of FGTL, we verified stable syngas production performance of AATG process at a pilot plant of which capacity was 65 BPD-GTL equivalent by feeding several different concentration of oxygen mixed with nitrogen as an oxidizer during 200hrs at each test. In addition, we examined the effects that nitrogen gas and nitrogen compounds, which are generated by using oxygen mixed with nitrogen as an oxidizer in the AATG process of the pilot plant, have on the FT synthesis process. Moreover we identified technical problems to be solved in the application of the AATG Process to FGTL. Finally, we showed a result of the simplified feasibility study to apply AATG process to FGTL.
Detecting Hydrocarbon Reservoir through Inversion of Broadband Multicomponent CSEM Data and Joint Interpretation with Seismic Constraints
Authors: Rahim Mohamad Faizal Abd , Meju Maxwell Azuka , Bujang Awang Amirul Zakry Awang , Fuad M. Izzuljiad Ahmad , Majid Hani Noorashiqin A
Published: May 2016

This reference is for an abstract only. A full paper was not submitted for this conference.

Description

The marine Controlled-Source Electromagnetic (CSEM) method uses electromagnetic waves to detect resistivity contrast in the subsurface which can be used to distinguish between commercial and non-commercial hydrocarbon or brine. One of the limitations of conventional CSEM is depth resolution of subsurface structures. Multicomponent data offers partial remedies to this problem while combining with seismic improves vertical resolution. A stable iterative inversion scheme that permits occam and model based inversions have been developed to investigate these problems.

In this paper, joint interpretation of a gas field offshore east Malaysia using CSEM, well bore and seismic data is presented. Firstly, we carried out synthetic studies of multifrequency and multicomponent 1D occam inversion using a model derived resistivity log to determine the improvement in resolution achievable through this approach. Secondly, the similar approach is applied to a field data acquired over a gas field in east Malaysia. A model based constrained inversion approach is applied to the field data to recover improved estimates of model resistivity, not obtainable through Occam inversion. Depth determined from seismic horizons are used as a priori information in the inversion while resistivities are free parameters.

Application

Establish a working model for the application of the CSEM method specifically in the eastern Malaysia offshore basins.

Results

The inversion results of CSEM synthetic and field data is presented in detail.

The results are validated using existing wellbore and seismic data. Previous work have been mostly concentrated on synthetic data, while some of the work that was presented using field data lack the validation part which requires well bore information.

The synthetic studies confirm previous work by Key (2009), that broadband multicomponent inversion significantly improves model resolution. Results from the inversion of field data agree with well log but are a smoothed version. The use of seismic depth control is found to yield resistivities closer to the ground truth and is recommended.

The effective sequence of operations is formulated into a workflow that can be used in deepwater exploration surveys.
Maintaining Of Ageing Storage Tanks
Authors: Henry Neil
Published: May 2016

There are tens of thousands of storage in service, many well beyond intended service life and commonly over 25 years of age. The passage of time does not treat them all equally. Owners and operators of tank storage need to recognise the indicators of age and deterioration and have an understanding of why this occurs and the likely rate. Knowledge of how these problems originate and how they may be controlled is an opportunity to improve plant safety performance, gives confidence in condition and helps assure reliability of operation.

There are financial benefits that arise from effective management of ageing; therefore it should not be considered a burden on operations and maintenance. The presentation uses examples from industrial experience to demonstrate how to manage integrity and the benefits that may be achieved.

Introduction

Following over 30 years of involvement in a process plant operating in many different environments, a deep understanding has been gained of how equipment deteriorates and the influences of operating regimes on life expectancy. It is the intention of this paper to illustrate how to improve understanding of the condition of storage tanks currently in service and required to operate into the future

This knowledge has been gained by both working on management of integrity and extensive forensic failure investigation, of process equipment including storage tanks. The investigation objectives have always been focussed on not simply specifying the mechanism of failure, but also identifying the true root cause(s).

The knowledge has been used to assist in preparation of the UK HSE Research Report 509 on Ageing Plant and to evaluate the condition of many items of process equipment, in a wide range of industries.

Why is age important?

In simple terms, there was a great deal of process plant built in the 1950's to 1980's, which had little definition of its expected service life.

Following this time there was a beneficial running and maximising cash generation. These assets still appear to be able to operate, but there is limited data to base judgements of how long is the optimum service life.
Pinpointing Water Entries in Dead Horizontal Wells
Authors: Bawazir Mustafa Abdulrahman , Haji Ahmad Haji Nawawi , Zeybek Murat , Malik Shauket
Published: May 2016

Increased water production is often the cause of reduced well performance, decreased hydrocarbon production, and/or killing the well. Water entry must be pinpointed before the remedial work to shutoff the water and to increase well productivity. A standard practice for shutting off the water is by running an integrated multiphase production logging tool, which is challenging in horizontal wells due to the high deviation, wellbore conditions, and multiple flow regimes. The diagnosis of this type of well becomes complicated when the horizontal well is dead.

In this paper, three field examples are presented on data acquisition (logging) in dead horizontal wells, with subsequent interpretation to pinpoint the water entry interval(s). The first well was completed with an inflow control device (ICD). An integrated production logging run during shut-in identified a leak with crossflow from the blank pipe to the open hole. The water source was determined to be a zone above the completed intervals. The second example is an open hole completion. The well flowed after nitrogen (N2) gas kickoff and the water entry was pinpointed from the toe section along with the oil profile. The third example is also a horizontal open hole completion. This well did not flow naturally, despite N2 lifting for 8 hours. Logging was conducted while injecting N2. Repeated passes yielded consistent results in pinpointing the water entry interval, and the water entry was identified also from the toe section.

These field examples demonstrated that integrated job planning and integrated interpretation are essential to opening new opportunities for diagnosing dead wells and providing solutions. Guidelines and recommendations for logging dead wells are now available for these types of logging conditions.

Introduction

The objectives of running integrated horizontal multiphase production logging (MPL) tools are mainly to obtain fluid-flow profiles, determine the relative contribution of the reservoir intervals, and identify water/gas breakthrough intervals to provide data for water/gas shutoff operations. Integrated horizontal MPLs are also used to evaluate the performance of open hole horizontal producers (Al-Muthana, et al. 2008), the effectiveness of a well completion (such as smart completions) or workover operations (such as water/gas shutoffs).

Multiphase production logging is challenging in horizontal wells due to high deviation, wellbore conditions, and/or multiple flow regimes. In addition, there are many different scenarios that could lead to high-water production sources such as:· Tubing, casing, or packer leak· Flow behind the casing and problems in or near the wellbore such as poor cement· Water coning· Rapid breakthrough of water through fissures
Floating LNG - Groundbreaking Innovation Becoming a Reality
Authors: Stegenga Sander , Pek Barend Johan Jan
Published: May 2016

While today's volatile business environment - including the global financial crisis; technological advancements, maturing 'easy gas' developments, heightened environmental scrutiny and an overheated construction market may have delayed FIDs for LNG projects, this same combination of forces and trends have led to the energy industry's renewed interest in Floating LNG (FLNG) and a growing belief that its time may have finally come, at least for a few of the interested parties and as evidenced by Shell taking FID on the Prelude FLNG Project in Australia.

Floating liquefaction of natural gas or FLNG has captured the imagination of engineers and LNG business developers ever since it was first considered. The concept is simple, but attractive: "Let's put the LNG facilities directly over the offshore gas resource rather than processing and piping the gas long distances to onshore liquefaction facilities".

FLNG has huge potential to extend the portfolio of traditional LNG concepts necessary to meet the energy challenge of the 21st century. Technological and commercial challenges may have prevented FLNG succeeding for a long time, as evidenced by the fact that there are no FLNG facilities currently in operation, but the world's first FID has been taken in May this year and the Prelude FLNG Project will move ahead through detailed design and construction over the next few years. The market circumstances, the environmental circumstances, and the technical maturity lead us to believe that Shell FLNG has now grown up to become a very serious gas monetisation option and that this first FID will not be the last.

The technical concept of Shell FLNG with some of its key technical challenges, and the inherent safety approach applied throughout the design is described in this paper. The main focus is on some of the key technical challenges and choices made in the design.
Managing Structural Integrity of Offshore Platforms: Looking Back to Drive the Future
Authors: Piva Roberto , Latronico Margherita , Nero Andrea , Sartirana Stefano
Published: May 2016

The ability of a structure to perform its required function effectively and efficiently over a defined time period whilst protecting health, safety and environment is one of the major task to take into account especially for the old ageing installations.

Considering that actual industry and regulatory authorities require the management of integrity not only at the design stage but during the entire service life, a Structural Integrity Management (SIM) process was developed by eni e&p to monitor offshore fields in the world by means of appropriate programmes of periodic inspections and life-extensions assessments. SIM evolved over the last 25 years according to Company best practices. Considering that the underwater inspection of offshore installations is a complex and expensive activity, a risk-based approach was adopted by eni e&p to monitor platforms conditions as an efficient methodology to obtain cost-efficient and state-of-art inspection plans. The risk-based strategy for the development of inspection scopes of work requires a thorough understanding of susceptibility to damage, tolerance of damage, and actual conditions of a platform.

Due to the awareness that in-service inspection campaigns can only assess the local platform degradation due to environment, corrosion and accidental impacts, engineering activities as Ultimate Strength Methods are also performed with the purpose of investigating the global platform behaviour and safety level. This typically involves the use of nonlinear, large deformation analysis to determine the maximum loading that the platform can sustain without collapsing, even in presence of local damages.

According to these approaches, at present, about 100 offshore conventional platforms installed in Italy seas are monitored, with 40 of them recertified to extend their operative life over the design life. Eni e&p Integrity Assessment approach was also applied to old steel gravity platforms within-service life of about 40 years in the offshore Congo.