bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compact and Light Weight Equipment for Floating Production Systems
Authors: Sellman Erik , Mandewalkar Pavan , Sams Gary W 
Published: February 2015

Floating production systems present special considerations considering both mechanical aspects and well as process aspects for the crude oil dehydration train.
The effects of sea heave produces fluid dynamic forces inside the treaters and also mechanical forces on the supports of the process equipment, which require special attention for the design of the treater internals, supports and instrumentation. In addition to the amplitude of the roll and pitch of the facility hull, the frequency of these movements has an equally important role.
Through the use of advanced fluid dynamic designs and advanced electrostatic technologies, the dehydration and desalting equipment on a floating production system can be made more compact, thus reducing the required footprint on the process deck as well as the weight load on the floater.
This paper describes special design considerations for dehydration and desalting equipment for floating production and how these process vessels can be drastically reduced in size and weight while still maintaining the required process performance. We will also discuss special considerations for instrumentation, slosh suppression and operating procedures, in addition to the potential for additional production from upgrading existing treaters.
The paper also includes case stories with examples of compact equipment installed on FPSOs, SPARs, TLPs as well as semi submersibles.
Company affiliation: Cameron Process and Compression Systems
Presenter: Erik Sellman, Sr. Product Manager (erik.sellman@c-a-m.com)
Multinomial Logistic Regression for Bayesian Estimation of Vertical Facies Modeling in Heterogeneous Sandstone Reservoirs
Authors: Al-Mudhafer Wathiq J. 
Published: February 2015

Precisely prediction of rock facies leads to adequate reservoir characterization by improving the porosity-permeability relationships to estimate the properties in non-cored intervals. It also helps to accurately identify the spatial facies distribution to perform an accurate reservoir model for optimal future reservoir performance.
In this paper, the facies estimation has been done through Multinomial logistic regression (MLR) with respect to the well logs and core data in a well in upper sandstone formation of South Rumaila oil field. The entire independent variables are gamma rays, formation density, water saturation, shale volume, log porosity, core porosity, and core permeability.
Firstly, Robust Sequential Imputation Algorithm has been considered to impute the missing data. This algorithm starts from a complete subset of the dataset and estimates sequentially the missing values in an incomplete observation by minimizing the determinant of the covariance of the augmented data matrix. Then, the observation is added to the complete data matrix and the algorithm continues with the next observation with missing values.
The MLR has been chosen to estimate the maximum likelihood and minimize the standard error for the nonlinear relationships between facies & core and log data. The MLR is used to predict the probabilities of the different possible facies given each independent variable by constructing a linear predictor function having a set of weights that are linearly combined with the independent variables by using a dot product.
Beta distribution of facies has been considered as prior knowledge and the resulted predicted probability (posterior) has been estimated from MLR based on Baye's theorem that represents the relationship between predicted probability (posterior) with the conditional probability and the prior knowledge. To assess the statistical accuracy of the model, the bootstrap should be carried out to estimate extra-sample prediction error by randomly drawing datasets with replacement from the training data. Each sample has the same size of the original training set and it can be conducted N times to produce N bootstrap datasets to re-fit the model accordingly to decrease the squared difference between the estimated and observed categorical variables (facies) leading to decrease the degree of uncertainty.
Modelling and Imaging Through a Gas-Obscured Zone in Malaysia
Authors: Zhu Xianhuai , Sood Sanjay , McMahon Tim , Brewer Joel , Keys Robert , Mosher Chuck 
Published: February 2015

Description of the material
The study area is situated SB311 block of Malaysia. The tectonic evolution of the area is linked to the rifting of South China Sea. The image of the target in this study is affected by the shallow gas-obscured zone in the overburden. The goal of this study is to investigate new acquisition techniques and parameters capable of imaging through the gas-obscured zones, using advanced modeling and imaging technologies.

Application
Based on regional geology and seismic data, two sets of models containing "geobodies" filled or partially filled with gas were built. The geobodies were constructed based on the characters of seismic amplitudes and stratigraphy, and they were distributed above and below the top of KBB formation. P-wave velocities (Vp), S-wave velocities (Vs) and bulk densities (ρ) inside geobodies were modified based on Biot-Gassmann fluid substitution and the Xu-White Differential Effective Medium (DEM) method. A 15m thick of unconsolidated low velocity materials was added to model immediately beneath the water bottom to investigate the feasibility of P-to-S converted wave recording.

Results, Observations, and Conclusions
Acoustic modeling and RTM imaging have suggested that long offset (&gt;10 km) is required in order for undershooting. Any newly acquired long-offset 2D streamer data could not only have potential for imaging the base of KBB, but also assist reprocessing of existing 3D seismic data.
Elastic modeling followed by dual-velocity RTM has suggested that P-to-S converted waves have potential for imaging both top and base of the Kebabangan reservoir, even with the 15m thick of low velocity layer below the water bottom. This assumes that vector fidelity and coupling of the phones or nodes at the ocean bottom can be secured.

Significance of Subject Matter
With the recent advances of ocean bottom nodes (OBN) technologies, converted wave survey may have potential to solve for the obscured-zone imaging problems in Malaysia and other regions around the world.

Acknowledgement
We thank Robert Beham of Malaysia Business Unit and Brad Bankhead of Geophysical Technology at ConocoPhillips for supporting this project.
CFD Simulations and Experimental Validation of Sand Erosion on a Cylindrical Rod in Wet Gas Conditions
Authors: Wong C.Y. , Boulanger J. , Zamberi M.S.A. , Shaffee S.N.A. , Johar Z. , Jadid M. 
Published: February 2015

The paper analyses original wet gas data from laboratory experiments and computational fluid dynamics (CFD) simulations. Air and water containing sand particles are transported in a vertical pipe and eventually impact on a centrally located aluminium rod. To determine the surface material loss over the rod surface, the surface profiles of the rod before and after the erosion test are accurately measured by a coordinate measurement machine. Three types of flow regimes with sand are examined and simulated, namely, water only, slug and annular flows.
The application of CFD as an engineering tool for assessment of sand erosion in field equipment is highlighted as well as the application of erosion intrusive well monitoring devices (e.g. ER probes) in wet gas conditions.
CFD simulation results predict the maximum depth loss in liquid only and annular regimes within 12%. In contrast, erosion caused by slug flows is under predicted by 2 orders of magnitude. The material loss is more focussed on the central location of the rod in the wet gas condition than it is in the annular flow case. The material loss in the liquid only case is more distributed over the rod than the annular case. Experimental results for all the flows show higher erosion loss on the cylindrical rod on the pipe centreline than closer to the pipe wall.
The work has identified important areas for improvement and further development in CFD techniques as they relate to sand erosion in field equipment.
An Investigation on Factors Influencing In-Situ Emulsion Stability
Authors: W Razak Wan Nurul Adyani , Md Zain Zahidah , Zhang Yong  Sheng , Muthiah Chandramalar A V , Tusiman Fuziana , Hamdan Victor Hugo , Ohen Henry 
Published: February 2015

An oil sample, collected from the wellhead of a shallow sand of a Malaysian reservoir, was identified as a very stable crude oil emulsion. This micro-emulsion type crude could not been separated in field separation facilities by gravity settling alone. The emulsion was very stable that it required either a high speed centrifuge (40,000 ppm) or high doses of emulsion breaker to be demulsified. Hence, from the perspective of field operational cost, it is critical to further investigate the factors that have potentially contributed to the stability of the crude oil emulsions.
The field of interest has been producing for over 30 years and its reservoir pressure has dropped to a level very close to the original bubble point pressure. All the wells in the field are gas lifted to enhance well productivity. Due to the unconsolidated nature of the reservoir rock, fines migration was one of contributing factor to formation damage. The reservoir crude was identified as biodegraded with missing of intermediate components from the reservoir fluid composition. As such, a structured bottom-hole sampling program was developed and bottom-hole samples were collected below gas lift mandrels while the gas lift was shut-in to thoroughly investigate the contributing factors to the formation of the crude emulsions and to identify the in-situ status of the crude.
Potential factors which could contribute to the formation of stable crude oil emulsions include 1) mixing of two or more incompatible crudes; 2) emulsifying agents including surface active materials (asphaltenes and resins, organic acids and bases, injected surfactants or oilfield chemicals) and finely divided solids (clay particles, sands, asphaltenes, wax, scale etc.). This study has investigated several potential contributing factors related to formation of the stable crude emulsions. It was concluded that naturally occurring fines could be the major contributing factor for the formation of the observed stable crude emulsion from the reservoir under study. Effect of gas lift on formation of the crude emulsion was found very minimal since the crude was at emulsion state even at reservoir depth.
Floating LNG is Coming of Age
Authors: Choi Michael S. 
Published: February 2015

Global LNG trade is expected to more than double to more than 725 Mtpa by 2020. Some of the new projects will be developed with floating LNG (FLNG) technologies, perhaps even with a full floating LNG chain: FPSO for LNG production in the field, offshore LNG transfer to shuttle tankers, and floating receiving terminal that leads to the eventual gas distribution grid.
There are already many floating LNG receiving terminals operating successfully in the world. Now that construction has started on the Shell Prelude FLNG, floating LNG chain will finally be completed in 2016. Undoubtedly, more projects will follow. The economics of floating LNG is too compelling. Major cost savings can be achieved by: eliminating well head/production platform(s); processing platform to facilitate gas treating, liquids recovery and stabilization; FSO for condensate and NGL; gas compressor and pipeline to an LNG plant onshore; with a FLNG system located in the field. There are also the intangible cost savings such as efficiency gains by constructing the entire system in a ship yard, material and manpower logistics, and shorter project duration.
Many technologies have combined to make floating LNG chain a reality. Reliable subsea well and control systems have mitigated the risks of well operations. Proven glycol (MEG) and other regenerative hydrate management systems have allowed longer tie-back distance. Cost-effective mooring systems for large FPSO, flexible flowlines and catenary risers have enable floating system of FLNG size to be considered seriously. However, it is the advances in floating LNG technologies that have evolved over the past 25 years that finally tipped the risk-reward equation. Technologies such as offshore ship-to-ship transfer, motion tolerant processing and rotating equipment, LNG spill and gas safety, and deepwater cooling have matured to an acceptable stage.
This paper will present the economic drivers that make FLNG chain attractive to producers and buyers alike, and the many conventional production technologies and those unique to FLNG that combined to enable a FLNG chain to be developed in confidence. FLNG chain should be of especial interest to Southeast Asia which benefit both as a producer and a consumer of LNG.
Deepwater Hybrid Riser Systems
Authors: Luppi Ange , Cousin Gilles , O'Sullivan Robby 
Published: February 2015

The future "Asia" deep water field developments will require new riser technologies to meet with the economical & operational demands, while ensuring safe and environmentally responsible applications.
The development of deep water oil & gas fields have motivated the need to develop new riser concepts (i.e. hybrid risers) in complement to the existing top tensioned risers, flexible or steel catenary risers.
The paper starts with a brief historical review of the "popular" Free Standing Hybrid Risers (FSHR) and the bundle Riser Towers (RT). Both riser concepts have been successfully installed in recent years; mainly in Angola, Nigeria, Brazil and Gulf of Mexico.
The Llatest evolution on hybrid riser designs will be also presented such as the Buoy Support Risers (BSR, Brazil), the Free Standing Flexible Riser (FSFR) and the Multi-Line Free Standing Risers (ML-FSR); the latter being a riser bundle to be fully assembled & installed offshore.
Application:
The paper will include the riser design methodology with references to industry codes & standards, recommended practices, etc. Typical functional loads and environmental load case matrix will be presented. Outline installation procedure of each riser system, including typical marine vessel spreads will be presented, e.g. for "Asia" installation fleet benchmarking and (future) availability review.
The Specific aspects of each technology readiness for "Asia" applications will be discussed, including the pros and cons of each system will be discussed.
Results, Observation, Conclusions:
The riser systems shall be designed for Asia "cyclone" conditions (e.g. 10 000 years wave return period) for both short term strength robustness verification and long term fatigue analyses.
Typical functional loads and environmental load case matrix will be presented.
Significance of Subject Matter:
Outline installation procedure of each riser system, including typical marine vessel spreads will be presented, e.g. for "Asia" installation fleet benchmarking and (future) availability review.
The future "Asia" deep water field developments will require new riser technologies to meet with the economical & operational demands, while ensuring safe and environmentally responsible applications.
Through Tubing Perforation Through 3 Barriers; Tubing Plus Two Casing
Authors: El Abdein Ossama Zein , B Yahia Zaidil 
Published: February 2015

A brown field producing mainly from two main reservoirs, currently experiencing low reservoir pressures and high GOR ranging 400-1000 psig and 2000-20000 scf/stb respectively with about 17% average water cut. Re-perforation and adding new perforations are one of the key production enhancements activities for this field.
Two candidates were identified for additional perforation opportunities. Nodal analysis evaluation study based on reservoir parameters (permeability, water saturation, reservoir thickness) suggested oil can be gained by executing these opportunities.
The main issue in executing the perforation job was that the proposed perforation intervals are covered by 3 barriers which are the 2–3/8"tubing, 7" and 9-5/8" casing. Technical simulations and practical surface tests were performed to verify the integrity of the 2-3/8" tubing, and when shooting in multiple casings (7" Liner and 9-5/8" Casing). These tests were done to select the proper gun type, size and phasing (shot density) due to the limitation and risks associated with the through tubing perforation. The gun selected after the study was 1–11/16" strip gun with 2 SPF and 0 deg phasing.
The through tubing additional perforation jobs were executed with 20 ft and 135 ft for the two highly deviated (60-70 deg) candidate wells. These were the first job for PETRONAS Carigali in through tubing perforation through three barriers of tubing, liner and casing.
Very good results were achieved, where oil production increased by about 300 bopd and 200 bopd for the two wells respectively, and the WC% decreased from 45% to 0% for the first well due to higher reservoir pressure of the upper zone.
The successes of this application can enhance re-looking to many wells that have additional perforation ignored initially due to covering by tubing plus multiple casing which result in increasing oil production.
This paper shares the details of the well, the nodal analysis carried out to quantify the possible gain, the preparation for the yard tests and the evaluation in the gun selection.
New Design Method of Multi-Stage Hydraulic Fracturing in Shale Horizontal Well
Authors: Jianchun Guo , Bo Gou , Ting Yu , Jizheng Yi 
Published: February 2015

In recent years, China has a rapid development of shale reservoirs. QianJiang lacustrine shale oil reservoirs in Jianghan Basin are similar to Bakken shale where Multi-stage hydraulic fractured horizontal wells have been proven to be an effective method for reservoir development. In this study, we propose a novel three-step design method for Multi-stage hydraulic fracturing. Firstly, feasibility study on the formation of fracture network was applied to Q2 well by the analysis of brittleness index, the difference of horizontal stresses and the characteristic of natural fissure. Meanwhile the suitable fracturing fluid system was selected and optimized. Then, the fracture network is treated as a high permeable zone. The number, volume and permeability of high permeable zone represent the stimulated reservoir volume and these parameters were optimized by numerical simulation. At last, optimization of treatment parameters (scale and perforation mode) were conducted by the relationship between fracture network parameters (number, volume and permeability) and treatment parameters.
We applied the new design method in the first shale oil horizontal Q2 well in Jianghan Basin. Evaluation of postfracture data indicated that the new design method was proper and easy to use.
The paper describes a new and convenient design method of multi-stage hydraulic fracturing in shale reservoirs. The lessons learned from fracturing in shale oil formation were also discussed. Finally, further information about stimulation of shale oil formation in Jianghan Basin was provided.
Optimisation of Autonomous Vehicles and Corresponding Docking Stations in Offshore Environment
Authors: Soofi Khalid A. , Lu Fang , Shu Zhichao , Hasenbein John , Morton David 
Published: February 2015

This paper describes in detail an optimization model that provides a range of required number of autonomously operated vehicles (AUV and/or Drones) to monitor hazardous objects in offshore environment. In addition to the number of AUVs required it also calculates the number of docking stations required to service these AUVs. Finally, an attempt was made optimize the location of the docking stations. The paper will describe the general theory and an example application to monitor ice floes in offshore Arctic as described next.
Arctic offshore exploration and development is inherently complicated due to harsh environment caused by extreme cold temperatures as well as the sea ice environment. The sea ice floes are dynamic in nature and have variable spatial size, thickness, speed and directions. The modern satellite imagery (particularly Synthetic Aperture Radar with its all weather capability) provides a powerful tool to get the size, speed and direction of the floes. However the ice floe thickness is not readily discernible from satellite images and attempts to calculate the thickness directly from satellite imagery have yielded mixed results.
One method is to make use of Autonomous Underwater Vehicles (AUV) which can be equipped with upward looking sonar (either in single beam or a multi-beam mode) and then sent to hazardous sea ice floe on command. The idea is that AUV will then make all the required profiles of the ice floe underside providing concrete information about the thickness and then report back to the control center where a decision could be made whether we need to initiate an ice management response or not. If we are to use the AUV and ancillary docking stations to measure sea ice thickness then we need to know what is the suitable number of AUV and corresponding docking stations required for a near zero tolerance of failure (i.e. failed to detect a hazardous sea ice floe based on its thickness). We decided to solve this problem using a linear mixed-integer programming method.
Successful Installation of a Completion System for Gas Migration Prevention
Authors: Pleasants Charles , Joseph Basil , Glynn John , Munshi Ammar , Knebel Mark 
Published: February 2015

Completion systems will be presented for prevention of gas migration composed of an annular casing packer with remote-set technology activated by either an acoustic wave generator or casing wiper plug (CWP) with a magnetic array. Proven and reliable zero-extrusion gap element technology provides a gas-tight annular seal while reliability is enhanced by eliminating all communication ports and potential leak paths between the packer's ID and casing annulus. Design and qualification of these systems will be discussed along with the recent successful field installation of a shallow depth 18 5/8" × 24" system in a Sakhalin Island offshore well.
There are three main benefits of these systems. They provide a reliable mechanical barrier to flow after cementing which can result in a significant financial impact to the operators and their service providers. They eliminate issues with annular casing pressure (ACP) and sustained casing pressure (SCP). They also provide a permanent seal between casing strings that reduces risks of costly plug and abandonment (P&A) operations.
One system for shallow depth applications employs an acoustic wave generator at the rig floor to initiate the setting sequence upon completion of cementing operations. Another system activates the packer setting sequence with the CWP during cementing operations. An optional contingency setting sequence can be programmed prior to deployment and later deactivated if not required.
Industry standards are focused on reducing annular flow prior to, during, and after completion of primary cement jobs. While these changes will improve annular isolation, conventional cementing contains fundamental limitations that complicate control of shallow gas hazards and water flows. The above completion systems will help alleviate these concerns.