bluuebunny/crossref_metadata_2025 huggingface dataset:
The Subsea Sand Management Challenge – What to Do with the Sand?
Authors: Rawlins Charles H. , Ditria John C.
Published: April 2019

Sand is a limiting design factor for facilities in terms of operability, throughput, and maintenance. These effects are more critical when dealing with subsea processing due to the equipment access and risk exposure. Technologies for erosion management, sand separation, and solids disposal are well proven for surface facilities. For example, the wellhead desander, located upstream of the choke, effectively separates sand from the multiphase well flow and can be marinized for subsea use. However, the crucial question is "What to do with the sand?" This white paper provides a focal point for the discussion on sand management in subsea processing. The broad categories for dealing with sand include neutralization of the effects, improvements in conventional design, and separation with disposal. These categories have been analyzed based on the conventional design, treatment of the solids, and removal of the solids. More than thirty discrete treatment routes were surveyed, including conventional production limits, flow path modification, chemical treatment, sand cleaning, mechanical attrition, slurry fracture injection, and accretion disposal. Many of these technologies have analogues in other particulate processing industries that can be adapted to upstream oil and gas production. This work is part of ongoing research in Facilities Sand Management with the goal of improving the hydrocarbon recovery through inclusionary sand production.
Maximize the Recovery Factor of Offshore High Water Cut Reservoir
Authors: Ma Kuiqian , Sun Zhaobo , Shi Hongfu
Published: April 2019

As the Offshore oilfields enter the high water cut stage, it encounters new and prominent problems such as difficulty in developing remaining oil, increased water breakthrough and rapid decline in production. How to maximize the recovery of high water cut offshore reservoirs and improve economic efficiency is a challenge.

This paper reviews the lessons learned on how SZ field improves water injection to stable reservoir pressure. Architecture unit-based well pattern improvement, Increasing injection and big-pump enhanced liquid production including renovation and capacity expansion of Water treatment system; Polymer flooding, Modifying reservoir flow pattern with Gel Treatment, Polymer Microspheres.

The wells display positive responses from the water injection. The responses include stable reservoir pressure, slower production increase, and slightly water cut increase. Enough and high quality water injection is extremely essential to maximize the recovery of a mature offshore heavy oil.
An Experimental Study of Using Plasma Shock Wave for Rock Damage
Authors: Cai Zhixiang , Zhang Hui , Li Jun , Yang Maolin , Yu Qing , Zheng Jiadong , Liu Kerou
Published: April 2019

Plasma shock wave (PSW) has been proven to be able to destroy rocks and improve the ROP for conventional rotary drilling. The aim of this paper is quantify the damage caused by PSW generated by different discharge energies, and to study the mechanism and characteristics of PSW damage to rocks.

The PSW has been extensively used in many areas, such as alternative fracturing. In the tests, the PSW reactor generated the electrohydraulic effect to convert electrical energy into mechanical energy, which was sufficient to destroy the hardest rock. Firstly, the experiment was carried out using concretes instead of real rocks. Secondly, three types of discharge energy were used to generate PSW to damage samples. Finally, the amplitude attenuation coefficient (AAC), the damage variable and the drillability were used to quantitatively analyze the damage of the samples.

Experimental results showed that samples were impacted to produce many circular holes and cracks and the damage to samples increased as the energy increased. However, when the energy rose to a certain extent, there was a gradually decrease in the growth rate of damage. In addition, it was found that the AAC measured at different locations was different for the same sample, which indicated that the internal damage of a concrete sample produced by the PSW was anisotropic. Finally, the average drillability was improved after the sample was subjected to PSW impact.

The findings gained will help understand the mechanism by which the PSW destroys rocks It also provide some methods to quantitatively evaluate damage of rock.
Application of Data Science and Machine Learning Algorithms for ROP Optimization in West Texas: Turning Data into Knowledge
Authors: Noshi Christine Ikram
Published: April 2019

A high rate of penetration (ROP) is considered one of the most sought-after targets when drilling a well. While physics-based models determine the importance of drilling parameters, they fail to capture the extent or degree of influence of the interplay of the different dynamic drilling features. Parameters such as WOB, RPM, and flowrate, (Mechanical Specific Energy) MSE, bit run distance, gamma ray for each rock formation in West Texas were examined. Ensuring an adequate ROP while controlling the tool face orientation is quite challenging. Nevertheless, its helps follow the planned well trajectory and eliminates excessive doglegs that lead to wellbore deviations.

Five different Machine Learning algorithms were implemented to optimize ROP and create a less tortuous borehole. The collected data was cleaned and preprocessed and used to structure and train Random Forest, Artificial Neural Networks, Support Vector Regression, Ridge Regression, and Gradient Boosting Machine and the appropriate hyperparameters were selected.

A successful model was chosen based a minimized deviation from planned trajectory, minimized tortuosity, and maximized ROP. A MAE of 10% was achieved using Random Forest.

The algorithms have demonstrated competence in the historical dataset, accordingly it will be further tested on blind data to serve as a real-time system for directional drilling optimization to enable a fully automated system.
Reducing Costs in Building a Dataset Using Deep and Active Learning
Authors: Castro Filipa , Costa Pedro , Marques Filipe , Parente Manuel
Published: April 2019

Deep learning, a subset of machine learning, allows computers to perform certain tasks, such as image or video recognition, with human level performance. However, deep models need huge amounts of data to learn from, which requires that experts spend their time in the repetitive and non-scalable task of labelling datasets. Active learning suggests that one can minimize the cost of annotation if a model is allowed to smartly choose the best data samples to be labelled. Therefore, we propose a deep and active learning approach that aims to minimize the labelling effort while maximizing the performance of a model for a certain task. We present the task of detecting fish in Remote Operated Vehicles (ROV) videos as a real world problem in which our framework can be successfully applied. To start with, we demonstrate that active learning outperforms random sampling, which is the simplest approach for building a dataset. Besides, we study several active learning settings for the given task, namely different acquisition and aggregation functions. Finally, the proposed methodology is shown to achieve top performance in detecting fish by using only 19% of the available data, thus reducing the cost of building our fish dataset by more than 80%.
New Pressure Sensor Technology in the Offshore Industry
Authors: Andrew David Alexander
Published: April 2019

A new pressure sensor technology packaged with a target for high stability and high reliability applications has been released, a single crystal integrated capacitance sensor that shows promising results for use in subsea and offshore environments. This paper details the laboratory results of qualification tests with a comparison to industry-leading technologies and presents some examples of how this sensor technology can be used to benefit the industry. Design validation testing was undertaken to full transmitters, in many cases with a direct comparison to quartz-based sensors.

This technology could open doors to new applications, and it can be configured to the target application. The use of the sensor in certain applications has the potential to reduce costs and increase yield in offshore exploration and production. The qualification data presented here could provide insight into available transmitter capabilities.

The single crystal integrated capacitance sensor could fill a gap in the industry for a sensor that stabilizes rapidly to thermal effects while exhibiting excellent long-term drift behavior. The thermal transient error is less than that of the quartz sensors it was tested against, and it allows for larger, continuously changing thermal gradients, with fewer errors. This sensor also allows for an increase in duration between zeroing, unlike typical piezoresistive sensor specifications.

The packaging and electronics are customizable for a wide array of solutions. The configuration of the transmitters detailed in this paper was specifically tailored toward data rates of 1Hz or less, 175°C operation, and tolerance to H2S containing environments. Future possibilities can target higher resolution, data rates, and alternate temperatures.
50 Years of Offshore Technological Innovation Illuminates Millennia of Archaeological Discoveries
Authors: Faulk Kimberly L.
Published: April 2019

For millennia, humanity has and continues to leave imprints on the physical world. Archaeologists have often turned to technology for help in interpreting these past imprints. This is especially so in the realm of underwater archaeology where sites may range from submerged prehistoric landscapes to what was for thousands of years one of human kind's most technologically complex objects, the ship.

Since the close of the Second World War, offshore technology has increasingly created opportunities and tools for subsea scientists to better map, explore, and understand both our natural world and humanity's interaction with it. The growth of offshore oil and gas exploration technology did not go unnoticed by archaeologists who were quick to modify these technologies and create new methodologies to use them for site analyses.

Starting with shallow water locations and ultimately moving into ultra-deepwater, marine archaeologists in the energy sector have greatly benefited from technological improvements originally aimed at the exploitation of offshore oil and gas. Beginning with echosounders, side-scan sonars, and magnetometers in towed arrays, before moving into high-resolution side-scan sonars, multibeam bathymetry and multibeam backscatter systems, subbottom profilers, and gradiometers, improving technologies have directly impacted marine archaeology.

This paper provides a review of the technologies archaeologists have appropriated for the purposes of revealing humanity's past with examples of some of the discovered sites from around the globe.
The Definition and Manufacture of a Seawater Compatible Surfactant for an Offshore Chemical Enhanced Oil Recovery Pilot
Authors: King Timothy E , Doll Mike J , Crom Lori A , Barnes Julian R , Kunkeler Paul J
Published: April 2019

Experiences from a chemical supplier perspective are presented to define, optimize and manufacture a surfactant for use with seawater in an offshore enhanced oil recovery (EOR) test. This includes laboratory screening test results followed by quality control checks during manufacture. The surfactant concentrate was successfully manufactured, diluted with seawater, and injected as the main component of a surfactant-polymer (SP) formulation.

A branched C12,13-alcohol-7PO-sulfate surfactant was designed for use with seawater. Particular pH buffer chemicals were screened for inclusion with the manufactured surfactant concentrate to give compatibility with seawater. The optimization of the surfactant concentrate with buffer included tests to assure acceptable aqueous solubility, storage stability and rheology. A quality control protocol was used that included decision gates with the operator and key stakeholders.

Laboratory testing showed good aqueous solubility of the branched C12,13-alcohol-7PO-sulfate in seawater with about 3.5% TDS and 1800 ppm divalent ions (minor calcium and major magnesium ions). The pH buffer selected for this application gave a pH of 7 to 9 to: Prevent precipitation of Ca and Mg divalent cations that could otherwise lead to fluid injectivity issues, andKeep the pH stable and above 7 (preventing acid-catalyzed hydrolysis of the sulfate group) for good storage stability of the surfactant concentrate from time of manufacture to time of use.

Ultimately, a 15% AM surfactant concentrate with Newtonian viscosity characteristics was manufactured and deployed due to transfer equipment handling requirements. However, for the future, concentrations of 70+% AM, also with Newtonian rheology, are possible for deployment.

Implementation of the surfactants in EOR to date has been largely restricted to onshore applications due to the challenges associated with offshore use. This paper provides a real-world example of the manufacture of a surfactant concentrate that was used in an offshore SP field project from the perspective from a chemical supplier. Information relating to the quality assurance and control during surfactant concentrate upscaling is also critical and included in this paper.
Observations and Modelling of Deep-Water Circulation in the Colombian Caribbean
Authors: Jaramillo Sergio , Morey Steven L , Cardona Yuley , Guarin Manuela , Williams Benjamin
Published: April 2019

In the deep waters of the Colombian Caribbean in situ measurements of current speed and direction in the water column are scarce. To address this gap, we conducted a 1-year metocean field campaign that included the deployment of three instrumented moorings at 1400 m, 2160 m and 3675 m water depths. We present results from these new observations and from numerical modelling of the long-term circulation in the Colombian basin.

Moorings were designed to obtain current speed and direction through the full water column, with higher resolution near the surface and near the seabed. To examine the spatial variability of the observations, hydrographic measurements were conducted during deployment and service visits to the moorings. To better understand the deep-water dynamics of the region, two numerical models (NCOM and ROMS) were configured to simulate 20-years of circulation in the Colombian Caribbean.

Measurements at the northernmost and deepest mooring near the Guajira Peninsula record several anti-cyclonic eddies moving generally towards the west with speeds upwards of 1 m/s in the top 1000 m for periods of up to one month. Observations from 1000 m down to 3 m above the seabed at this deepest mooring are remarkably coherent in speed (~0.2 m/s) and direction (NNE). This mooring also recorded five events resembling topographic Rossby waves with periods of ~60 days and clear bottom current intensification. The upper circulation at the two moorings near the central Colombian Caribbean flows mainly towards the NE and presents several energetic episodes (maximum speeds ~1 m/s). Measurements at all sites show many eddies that are not confined to the near-surface layers but are submerged below 200 m with no clear connection to the upper circulation. Statistical comparison with HYCOM hindcast reanalysis data shows good agreement near the surface, but a rapid deterioration of model skill below 500 m depth. The two models configured to simulate the circulation inside the Colombian basin show good general skill, but still misrepresent some of the observed current features.

Our observations show that in the Colombian Caribbean, the northern region’s upper 1000 m are dominated by the NW-flowing Caribbean Current and the anti-cyclonic eddies entrained in it, while below 1000 m to near the seabed, circulation is controlled by a nearly vertically-uniform, deep current moving in the NNE direction. To our knowledge, this is the first time that this deep current system and its oscillations are reported. The central and southern regions are dominated by the variations of the Darien Countercurrent in the upper layers, and by flow-topography interactions near the seabed. Submerged eddies are common to all areas observed.
High H2S Gas Field Monetization: A Novel Approach
Authors: Jariwala Ankur
Published: April 2019

As per EIA, 40% of the world reserves are sour. This has imposed significant challenges and economic burden to monetize ultra-sour gas fields with H2S levels much higher than 5 mol% in the raw gas. Currently most of the ultra-sour gas fields are monetized by using conventional treating technologies like amine solvent process followed a Claus based process to produce sulfur, Sulfur recovery unit and Tail gas treatment unit, SRU-TGTU. This process is extremely capital and operating cost prohibitive as standalone processes. Also, the overall Sulfur production requires a local demand to address overall sulfur disposal cost. With growing number of fields with higher than 5-36% H2S, ultra-sour fields, it’s difficult for operators to maintain healthy production profits while producing such large quantity of sulfur. With ultra-sour gas production, it has many Health Safety and Environmental (HSE) challenges.

A new gas treating technology approach is developed to address ultra-sour fields. The approach is using hybrid process by using state of the art H2S removal membranes to do bulk separation of H2S upstream followed by small amine and Claus plant. This is ideal solution where unique membranes have ability to withstand high H2S environment without altering its performance. These membranes will separate H2S enriched stream which is ideal for reinjection or potentially used for Enhanced Oil Recovery (EOR). The membranes retain maximum hydrocarbons in the high-pressure product gas which very valuable in gas production. Low pressure H2S rich stream is water dry and can be reinjected directly. These membranes will also address CO2 capture along with H2S removal.

Using combination of unique membrane technology with smaller amine and Claus plant will reduce the overall CAPEX and OPEX requirement for a given project budget. Membranes are much safer and does not have any emission issues. This will allow plants to be much more HSE safe. Having lower CAPEX and overall lower total cost of ownership (TCO) will allow operators to monetize ultra-sour gas fields and provide better return on investment compared to standalone large sulfur plants.
Design and Performance of a TLP Type Floating Support Structure for a 6MW Offshore Wind Turbine
Authors: Guillaume Bonnaffoux , Christian Bauduin , Christine Bertolotti , Cecile Melis , Timothee Perdrizet , Yann Poirette
Published: April 2019

The objective of this paper is to present the design and performance of an offshore floating wind turbine support structure and associated station keeping system, for a commercial 6 MW turbine. The results reported in this paper are based on a joint desk study performed by SBM and IFPEN for the development of this new floating support structure concept.

The proposed system has been extensively analyzed thanks to time domain simulation software. Time domain models incorporate the wind turbine, the station keeping system, as well as structural components of the floating foundation. The system’s behavior has been assessed for a variety of environment conditions and turbine conditions (operating, idling, fault), resulting in an extensive design load case table. In addition to the nominal system, a number of sensitivities have been investigated to test the system response to various effects: marine growth accumulation on the floating support structure, anchor position tolerance, variations of water level.

Results produced during this study show the good performance of the proposed floating wind turbine support structure and components. The proposed arrangement is capable of sustaining 20 years of operation with environment conditions up to the 50-year return period. The motions of the floating support structure are beneficial for the turbine performance, with low inclinations and low nacelle accelerations. As a consequence of these floating support structure’s low motions, the floating offshore wind turbine production is only marginally lower than the production of the same turbine on a fixed offshore foundation in the same environment. Production can occur up to the 50-year joint environment conditions.

The work presented in this paper formed part of a design dossier independently reviewed by a certification body to obtain an ‘Approval in Principle‘ for the development of the floating support structure. The study has shown that the floater motion characteristics allow similar turbine production levels to be achieved by a turbine on a fixed offshore foundation, providing support to move of floating offshore energy production.
Accurate Frequency Division Inversion Based on Seismic-Well Fusion in Seismic Data Superposition Area
Authors: Gao Wenbo , Wang Mingchun , Chen Wenxiong , Zhou Xin , Mao Yue
Published: April 2019

Recently, the western part of Bohai has obtained significant commercial oil discoveries in Guantao group for the first time. The old seismic data is wide, but the bandwidth is narrow. The new data bandwidth is large, but the coverage is small. Besides, the impedance difference of sand and mudstone is small. The traditional impedance inversion can't distinguish them effectively. It's very important for the next evaluation to get seismic data that can reflect reservoir effectively.

We propose to use geophysical technology to fuse high-frequency and low frequency information of new data into old data. First, the reflection coefficient of the drilling bypass is extracted. Second combined it's high frequency information with the low frequency information of the reflection coefficient which is calculated by the drilled wells. After that, the fusion coefficient is used as the sample information to invert the frequency attributes of the old data. Finally, the high frequency, the low frequency information of frequency inversion and the intermediate frequency information of the old data are fused to obtain the broadband inversion data.

In the new and old seismic data superposition area, the frequency band characteristics of the comparison inversion data and the new data are found to be quite similar. Frequency band features are also very similar. It shows that the inversion data are true and reliable. Comparison between drilled wells and the inversion data, compared to the old seismic data, the inversion data of the Guantao formation reservoir thickness is more than 8m can be effectively reflected, and the old seismic data have seismic response when the reservoir thickness is more than 15m, and the response of some reservoirs is not obvious. The seismic resolution of the inversion data is improved effectively. To sum up, the frequency division attribute inversion based on seismic well fusion can effectively improve the bandwidth of the difference data in the rear area of seismic data, and improve the resolution of seismic data.
Self-Healing Functionality in the Protection of Off-Shore Oil and Gas Assets
Authors: Wilson Gerald O , Kasisomayajula Subramanyam V , Dayton Christopher R , Navarro Aidnel G
Published: April 2019

In a 2016 NACE report, the global cost of corrosion was estimated to be about US$ 2.5 trillion, which amounts to about 3.4% of global Gross Domestic Product (GDP). Industries such as oil and gas that maintain a disproportionate amount of their assets in extremely corrosive environments bear a disproportionate amount of these costs. Add to these costs the environmental and individual safety consequences of material failure due to corrosion and the case for investing in new technologies geared towards improving corrosion protection can hardly be overstated. In this paper, we report on novel additives which leverage the incorporation of microencapsulated healing agents into coating systems with a view towards lengthening their service lives and that of their underlying substrates while minimizing the opportunity cost of downtime associated with maintenance. These self-healing additives have been evaluated in a broad range of coating systems selected to provide the asset owner/operator with a range of options aimed at delivering improved readiness and cost savings across the oil and gas value chain.

Here, we provide an overview of evaluations performed in in a range of coating chemistries. For all the data reported, the efficacy of the self-healing additives was evaluated by incorporation into a coating system and comparing relative to the equivalent commercially available coating. For all the comparisons, the control and the self-healing versions of the coating were damaged by scribing followed by equilibration at room temperature for a minimum of 24 h prior to accelerated corrosion testing.

A summary of the performance improvements observed upon incorporation of the self-healing additive into coating formulations is provided in Figure 1.
Systems Engineering Principles to Enable Supplier-Led Solutions
Authors: Falk Kristin , Ulsvik Ole Kaare , Engen Siv , Syverud Elisabet
Published: April 2019

This paper explores how the oil and gas industry has applied systems engineering and lean product development principles to develop a Configure-to-Order strategy and enable supplier-led solutions. The purpose has been to enable shorter time to delivedy and lower cost. We have developed a life-cycle model for customer and supplier needs. Our model from the subsea industry is based primarily on own experience and needs to be further explored and validated. The paper also exemplifies challenges connected to a successful implementation of a Configure-to-Order strategy. There are three essential elements. The first element is that customers must communicate functional requirements with associated performance requirements. The second is that engineers must consider modularity during product design. And, the third is that supplier gets access to relevant operational data in a way that does not harm the customer. The principle of respecting both customer and supplier need and viewpoints is a key to success when it comes to supplier-led solutions.
Recalibration of Axial Pile Capacity Methods
Authors: Van Dijk Bas , Kaltekis Kostas
Published: April 2019

The Lehane et al. (2017) pile load test (PLT) database (new PLT database) is one of the results of a joint industry project (JIP) to investigate the reliability of (CPT based) axial pile capacity methods for driven piles. The database contains results of high quality axial load tests of piles in sand and clay. This database was used to recalibrate five pile design methods for axial pile capacity of offshore piles. The methods considered were:

For sand:

Fugro-05 (Kolk et al., 2005)

Fugro-05 (ISO, 2016)

 

For clay:

Kolk and van der Velde (1996)

Centre for Civil Engineering Research and Codes (CUR, 2001)

Van Dijk and Kolk (2010)

The recalibrated methods obtain a lower coefficient of variation (COV) and a better prediction of the mean of the measured capacity of the PLTs of the new PLT database and hence they can be considered more reliable than the original methods.
Validation of Cost-Effective Design Methods Using Hydrostatic Head for High Pressure High Temperature Applications
Authors: Pathak Parth D , Katsounas Nicholas P
Published: April 2019

Validation testing of the subsea equipment designed for HPHT applications using external pressures due to the hydrostatic head can be a challenge. This paper presents the tests performed to validate the design methods proposed in OTC-27891-MS. Use of a seawater hydrostatic head enables 15,000-psi-rated subsea equipment to higher than 15,000-psi applications without the additional costs related to developing new 20,000-psi-rated equipment. The design methods utilize the guidelines in technical report API Technical Report 17TR8 and load cases per API Technical Report 17TR12.

Three primary validation tests are presented—one to validate the pressure-containing equipment, one to validate the pressure-controlling equipment, and one to validate the equipment subjected to trapped air voids. To validate the pressure-containing equipment, a 20,000-psi valve block was pressure tested to internal pressure up to 25,000 psi, with application of 5,000-psi external pressure simulating 10,000-ft applications. The valve block was strain gauged at multiple locations including the body and the bolts. The strains predicted using the finite element analysis (FEA) methods are then compared to the strains evaluated from the tests. For the pressure-controlling equipment, a 15,000-psi valve was tested to 17,000-psi upstream pressure and 2,000-psi downstream pressure across the gate of the valve assembly, with 2,000 psi external pressure, for various operational load cases to monitor the effects on performance of the gate valve and the actuator mechanism. The final validation test was performed for stem seals of the gate valve assembly, which are exposed to trapped air voids. These are tested separately to their absolute working pressures higher than 15,000 psi per the API 6A Annex F test regime.

The tests for the pressure-containing equipment showed that the actual strains in the valve block and bolts correlated well with the FEA. For the pressure-controlling equipment, various upstream and downstream pressure combinations and functions were tested which showed that the effect is minimal on the actual performance on the gate valve and the actuator and that the pressure-controlling equipment can handle the various expected differential pressure load cases. The stem seal test increased their absolute working pressure rating. These types of tests provide good guidelines on what the typical subsea equipment manufacturers can perform to validate their equipment with similar design considerations.

The paper presents the various practical tests that can be performed to validate the verification analysis utilizing the external pressures due to seawater hydrostatic head. Validation is a necessary part of the design process and can be extremely expensive and nonfeasible for subsea equipment. This paper presents a practical approach for validating the design verification analysis for subsea equipment.
Innovative Use of the CPT to Assess the In Situ Degradation of an Offshore Overconsolidated Clay
Authors: Shonberg Avi , Harte Michael , Tucker Greg , Rattley Mike , Gibbs Paul
Published: April 2019

The cone penetrometer test (CPT) is used extensively for the assessment of ground conditions for offshore wind farms due to its relative speed, accuracy and continuous profiling capability. For a recent offshore wind farm project in the North Sea, the CPT equipment and CPT procedure were innovatively modified to assess the residual strength and cyclic degradation properties of a highly overconsolidated clay in situ. The CPT equipment was modified to include a second sleeve, located behind the main sleeve, to assess the in situ shear strength degradation with a fixed shear strain. The CPT test procedure was modified to include a ‘cyclic CPT’ test, or ‘CPTc’ test, whereby the CPT was cycled up and down, to assess the in situ cyclic degradation of the soil at large cyclic strain amplitudes. The in situ tests gave consistent results in line with expectations for a highly overconsolidated North Sea clay. After comparing the results of the CPTc, the dual sleeve CPT and select relevant laboratory tests, a consistent response indicates the applicability of using these innovative in situ tests to assess the degradation of the highly overconsolidated clay.
From Tanker-Ships to the First FPSO in the US GoM
Authors: Mastrangelo Carlos F. , Lan Christy M. , Smith Charles E.
Published: April 2019

During the 1970s, the Oil and Gas (O&G) offshore industry undertook the first few projects that exploited oil fields by using a tanker-ship as a hull to host its process plant and store the produced oil. Both the Shell project in the Castellon field in Spain and the Petrobras project in the Garoupa field in Brazil are considered pioneers of the Floating Production Storage and Offloading (FPSO) concept. The FPSO concept has many inherent advantages when compared to other types of floating facilities. However, the concept did not immediately become a preferable option for operators around the world. Throughout the 1980s, the industry did not experience a significant increase of FPSO-type projects. During this time, there was a clear preference for non-FPSO floating production units, despite the need for additional storage and a continuous export system. Additionally, port administrations treated all ship-shaped production units, including FPSOs, as tanker-ships. As such, they had to be compliant with International Maritime Organization (IMO) tanker requirements. This classification made it difficult to use FPSOs as permanent solutions to exploit offshore oil and gas fields. The IMO tanker requirements mandated that FPSOs could not stay on location longer than 3 years, although a 1-2 year extension could be granted, depending on inspections and other operational requirements. These requirements were enforced even if the operators and FPSO contractors designed the FPSO for a longer life. This paper describes the first steps, both regulatory and standardization of technical design requirements, in the approval process related to FPSO use for oil and gas fields. The paper describes how the United States (US) Environmental Impact Statement (EIS), and other initiatives between 1999 and 2001, paved the way for the US acceptance of FPSOs. Finally, the paper explains why the first FPSO in the US Gulf of Mexico (GoM) had a moored, single point, internal turret with a planned disconnection system as opposed to other design options that were evaluated and rejected.
Gas Hydrate Production Testing: Design Process and Modeling Results
Authors: Moridis George Julius , Reagan Matthew Thomas , Queiruga Alejandro Francisco
Published: April 2019

The objective of this study is to analyze in detail a process for designing by means of numerical simulation a field test of gas production from hydrate deposits, and to discuss modeling results associated with several such planned tests. The paper discusses comprehensively the data required for a reliable estimate of gas production, and provides insights into production conditions and test well operating parameters that can adversely affect a planned test. The design process begins with the development of a reliable geologic model. It is followed by an analysis of the system stratigraphy, the identification of the hydrate-bearing zones and the associated interlayers, the definition of the initial conditions (pressure, temperature, phase distributions, and geomechanical stresses), the identification of all key media properties (flow, thermal, geomechanical), and the definition of success criteria for hydrate production tests.

The geologic model is of paramount importance because it can define the system boundaries. We explore the relative importance of lateral vs. top and bottom flow boundaries within the context of the limited time frame of a field test. Initial pressures P in hydrate accumulations are relatively predictable as they are almost invariably hydrostatic. The initial temperature T distribution is important because T is the dominant parameter controlling the hydrate behavior. Knowledge of the P and T distributions are important in determining true time-invariant P- and T-boundaries. Other important initial conditions are (a) the spatial distribution of the possible phases and (b) the geomechanical stresses in the system and its surroundings. We discuss possible sources of the necessary data through analogs even when direct measurements are unavailable. We investigate the effect of heterogeneity in various parameters, and in the choice of the coordinate system. We explore the impact of spatial discretization, an important subject that has yet to be fully investigated. Finally, we provide modeling results covering a wide range of designs for production tests in oceanic and permafrost-associated hydrate deposits that describe fluid production and the flow and geomechanical system response, as well as implications for the well design and construction.

To the authors' knowledge, this is the first paper discussing in detail the recommended process for the design of field tests of gas production from hydrates, and of the key issues that can affect not only production but also the flow and geomechanical behavior of the system during the test and the definition of the well construction requirements.
Ocean Current Statistics in the Gulf of Mexico Derived from an Ensemble Approach
Authors: Srinivasan Ashwanth , Sharma Neha , Gustafson Drew , Iskandarani Mohamed , Knio Omar , Thacker Carlisle
Published: April 2019

Ocean currents are an important consideration throughout the life cycle of the many offshore projects. These currents are complex, three dimensional, dynamic and as yet poorly characterized in a statistical sense. Numerical ocean circulation models are increasingly sophisticated and are beginning to capture the structure and variability of complex ocean current systems. The starting point for model-based characterization of currents is a long time series of model outputs obtained at high spatial and temporal resolution. There are an ever-increasing number of model products, but it is not clear how to identify suitable products for a given application. Frequently, a familiar product is chosen that may not be the best choice. Here, we present an alternative approach wherein a collection of model runs, referred to as an ensemble, is used to estimate ocean current statistics at points of interest. Unlike other ensemble methods where the ensemble is used to estimate the statistics directly, we use the ensemble to construct a surrogate ocean model or an emulator using polynomial expansions. This emulator is computationally inexpensive to run and is used to sample the model outputs for large numbers of model inputs to generate full probability distributions of the model state, which can then be used to derive statistics required for design criteria. We have used the above technique to build an emulator for a numerical circulation model of the Gulf of Mexico. We present statistics of the Loop Current derived from this approach and briefly compare it with statistics obtained from measurements and other available long time-series of model outputs. Probability distributions for a sample point in the vicinity of the Loop Current are presented. It is shown that the technique can provide robust statistics and complements existing techniques.
Novel Technology Solutions Enable Phased Field Development to Maximize Returns and Minimize Risks
Authors: Skowronek Tyler , Kalia Akshay , Kjellnes Hans Fredrik Lindøen , Serrentino Ana , Chidiac Cedric , Mercer Ted , Holyfield Simon
Published: April 2019

The downturn has impacted our industry in many ways, not only in terms of budget cuts and headcount reductions but also in changing the way organizations work. The downturn has enabled the creation of novel technologies and efficient development plans such as phased development and early production systems that are transforming the industry, and the increased collaboration between operators and suppliers has been unprecedented. This paper discusses recent technology developments that have and will continue to reshape the approach to phased field developments.

For many years, the concept of phased field development has focused on reducing the expense of reaching first oil while planning the development for maximum recovery and deploying technology blocks that enable future add-ons for optimal asset return on investment (ROI). Game-changing efficiency resulting from earlier engagement with customers, paired with the latest technology and tools, can maximize the potential of a phased field development.

Using real-world development data as a basis, this paper details how operators can use current technology and tools to enable efficient phased field development. The case study discusses the benefits of using integrated field development and planning solutions that provide operators and suppliers a robust cloud-based collaboration solution for planning and evaluating various field development options and associated cost and schedules estimates at the click of a button. The paper then shows the impact that technology such as all-electric solutions, boosting and compression, pipeline solutions, and modular product solutions can have on the decision-making process for upcoming projects.
Modeling Method of Point Bar Internal Lateral Accretion Interlayers of Meandering River Reservoir Based on Reservoir Numerical Simulation Dynamic Response
Authors: Ye Xiaoming , Huo Chunliang , Shi Xinlei , Chen Rongtao , Yang Dongdong , Mao Yue
Published: April 2019

In the process of point bar internal architecture modeling, it is common to use local grid refinement method to model lateral accretion interlayers, which are often less than 1 meter thick but have a considerable impact on fluid flow. Due to huge grid amount and grid size difference, it often causes non-converging or converging too slowly of reservoir dynamic numerical simulation algorithm, which is not beneficial to practical application.

In this study, we proposed a new method to model lateral accretion interlayers based on reservoir numerical simulation dynamic response. Firstly, modeling target area of lateral accretion interlayers is defined by history matching results analysis based on the point bar level geological model. Then, the lateral accretion interlayers of the selected target area are modeled and equivalently characterized through transmissibility multiplier data instead of geometric parameters in numerical simulation model. Lastly, the multiplier value of transmissibility multiplier data is determined based on reservoir numerical simulation dynamic response.

The method of this paper only models the lateral accretion interlayers which have influence on fluid flow, which greatly reduced research workload than modeling the lateral accretion interlayers of the entire oilfield. The fluid seepage effect impacted by lateral accretion interlayers is characterized through transmissibility multiplier data; it has overcome the shortcomings of traditional local grid refinement method, and operation efficiency is greatly improved. The method has been successfully applied to model the lateral accretion interlayers for fine remaining oil distribution prediction in Q oilfield. Compared with traditional local grid refinement method, the computation time of numerical simulation is greatly reduced. The historical fitting rate of water content of a single well is grastly improved. Based on the new method, the water flooding degree coincidence rate between model prediction results and post-drilling logging interpretation is above 90%.

In this study, we proposed a new lateral accretion interlayers modeling method to improve the numerical simulation accuracy and efficiency. It can also be used in other sedimentary facies types such as deltas for internal architecture modeling.
Development and Demonstration of Novel Cryogenic Distillation Process for Offshore Gas Platform
Authors: Kim Yoori , Yeom Seungjong , Yoon Sekwang , Kim Jin-kuk , Kwon Suhyoung , Hwang Saebom , Shariff Azmi B
Published: April 2019

Natural gas consists of methane and other gases, which are mostly natural gas liquid (NGL), CO2, H2S and water. NGL generally refers the stream containing C2 or heavier hydrocarbons, mostly ethane and propane [5]. The recovery of C2+ components from the sale gas can enhance cost-effectivness in natural gas processing by selling highly valuable feedstocks for petrochemical sectors.

The schematic block diagram for the cryogenic distillation process widely-used in the offshore environments, is illustrated in Figure 1. Feed gas is pre-cooled before being separated in the distillation column operated cryogenic conditions. J-T valves or turboexpanders are commonly used for the expansion of gas stream which is introduced for providing necessary cooling or cold condition required for the process, while a compander may be applied to increase energy efficiency. The turboexpander-based cryogenic distillation process has been the most widely used for extracting NGL from natural gas because of its high energy efficiency and ethane recovery performance, compared to other processes [15]. Various process configurations for turbo-expander processes have been developed for improving energy efficiency or ethane recovery or adaptability [11, 13], which includes:

Gas Subcooled Process (GSP)

Cold Residue Reflux process (CRR)

Recycle Split Vapor process (RSV)

Single Column Overhead REcycle (SCORE)

Although there are differences in the configurations, in terms of heat recovery, power recovery and interconnectivity between streams, the unit operations and their sequences required for the NGL recovery through cryogenic distillation is more or less the same.
Overcoming Hurdles to Accelerate Data-Centric Ways of Working in the Energy Industry
Authors: Anand Binay , Krishna Kiran
Published: April 2019

Digitalization in the energy industry will substantially change engineering functions in the coming years and affect work on both capital projects and operating facilities. The focus of digitalization is not merely on the digital transformation, but on the use of digital technologies to create more value in core businesses while building the appropriate organizational capability and mindset. Underpinning use of digital technologies is the move to data-centric ways of working. This paper examines the preliminary challenges experienced in the move to data-centric ways of working and covers examples in three areas: People, Process and Technology.

Organizations have been digitizing for decades, but the digital revolution is only just beginning. There is mounting evidence that we are approaching a tipping point in the exponential advance of digital technology. However, the foundations on which these aspirations have been built are not that robust. The paper will focus on foundational aspects of the journey that, if done right, can accelerate the value capture of digitalization.

The following are some of the example issues covered in the paper in each area:

People: Restructuring organizational competencies, cultural change management and recognition and management of the generational continuum associated with the workforce.

Process: Complexity of project delivery across multiple organizations in the supply chain, the move from documents to data, and impact on business models that deliver document-based content.

Technology: Data standards and handover or transfer protocols, federated data repositories, plug-and-play tool integration and tool agnostic IT solutions.

The conclusion is a call-to-arms directed at the entire energy Industry, i.e., operators, EPCs, suppliers, construction firms, regulators, standards bodies, etc. to collaborate and set a robust foundation that is data-centric to accelerate the digitalization revolution.