bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Methodological Approach to System Design for Reliability for HPHT Environments
Authors: Amanat Asadullah 
Published: April 2015

Abstract
Ensuring the reliability and integrity of downhole completions systems and equipment for cutting-edge technology wells in the extreme environments of ultradeepwater Gulf of Mexico (GoM) is extremely challenging because of the stringent lifetime and high-pressure, high-temperature (HPHT) requirements set by customers. Although the American Petroleum Institute (API) provides specifications and recommended practices for design and qualification testing of various downhole equipment, those guidelines do not directly address design and testing at the system level.
Failure modes of downhole equipment are still not well understood because of limited historical field data and mission profiles. Implementing an effective and robust reliability and qualification program that analyzes completion systems at all phases of well completions can result in considerable financial savings and eliminate nonproductive time.
This paper presents the planning and execution of a robust Design for Reliability (DFR) and qualification program for downhole well completions systems including lower completions, upper completions and intelligent production systems. The program is a multidisciplinary approach that combines deploying state-of-the-art engineering analysis methods using proven mathematical models, validation/verification testing; and well-defined guidelines to minimize various critical failure incidents. During the planning phase, reliability analyses are conducted to understand and define all major risks in design and lifetime reliability during various phases of the well completion, i.e., from design to manufacturing and assembly to operations. Best practices from various product development functions are also implemented, including supply chain, reliability, manufacturing and operations.
The DFR and qualification program effectively optimizes cost and time without sacrificing quality and reliability by using upfront design optimization and analysis techniques, resulting in a system-level reliability and qualification plan that meets or exceeds the customer's quality and reliability requirements.
Automated Decision Support and Expert Collaboration Avoid Stuck Pipe and Improve Drilling Operations in Offshore Brazil Subsalt Well
Authors: Ferreira Ana Paula L. A. , Carvalho Daltro J. L. , Rodrigues Rogério M. , Schnell David M. , Thomson Ian J. , Baptista Rafael C. , Alves Sandro B. 
Published: April 2015

Offshore Brazil is a technically challenging drilling environment due to its size, depth, section length and lithology column characteristics. While drilling in this environment, operators often face nonproductive time (NPT) incidents such as stuck pipe, lost circulation, pipe failure, fishing, and plug and sidetrack. In some cases, operators are forced to sidetrack or even abandon wells after experiencing carnallite-related drilling difficulties.
Drilling through carnallite is challenging because its rate of creep is eight times greater than common halite, or rock salt. Information from wells drilled through similar deep salt sections show that the salt closure rate for carnallite can reach 0.0415 in./hr (1.05 cm/hr) compared to 0.0052 in./hr .01 cm/hr) for halite.
Unfortunately, NPT events repeat themselves in the course of developing a field. One of the reasons the events are not solved is that we are drowning in data. The event symptoms become lost or go unrecognized until it is too late. Early identification of symptoms as they occur while drilling in real time is critical to provide actionable information to the drilling team well ahead of the potential incident.
The methods used enable the drilling team to deliver wells on plan and meet budget projections by recognizing potential drilling problems before they occur. The process integrates three key elements; 24/7 real-time surveillance, case-based reasoning software and the knowledge base of the collaboration team. These three elements combine to provide a fast, practical, real-time solution to avoid NPT.
The multidisciplinary drilling optimization group, integrated with the operator's drilling team, used the automated decision support and timely collaboration for informed decisions, avoiding stuck pipe and saving rig days to free the pipe as well as potential time and cost for fishing, lost BHA and sidetrack.
This paper will illustrate an efficient method of preventing drilling problems before they occur with a decision support tool that provides real-time, case-based reasoning and expert collaboration for enhanced risk assessment and hazard mitigation. The paper provides a case history using the approach taken in the drilling of pre-salt well and discusses the lessons learned during the process.
Steel Catenary Risers (SCRs): From Design to Installation of the First Reeled CRA Lined Pipes. Part I - Risers Design
Authors: Gouveia João , Sriskandarajah T. , Karunakaran Daniel , Manso Daniel , Chiodo Mario , Zhou Daowu , Cao Lingjun , Rao Venu , Vargas Tomaz , Escudero Carlos 
Published: April 2015

Abstract
Steel catenary risers (SCR) have been a favored choice for recent ultra-deep waters field developments subjected to harsh environments and large floating production units (FPU) motions. The design of SCRs in such conditions is always a great challenge where the key issues are the fatigue near the hang-off and at the touch down point; clashing between lines, especially on fields with a large number of wells and high payloads on the production unit. This paper describes the solution provided by the Buoy Supporting Risers (BSR) concept which has recently been installed in the Santos basin offshore Brazil.
Subsea7 detailed the original concept of BSR system, from the design to fabrication and installation. The BSR concept combines several benefits to overcome the challenges of installing SCRs on ultra-deep waters, such as: allowing decoupling between installation of risers/flowlines and the platform, reducing payload on the production unit, very small dynamics transmitted from production unit to the risers, resulting in significant less fatigue issues. Also, the BSR concept reduces the risks associated with clashing and interference due to the smaller dynamics when compared to traditional coupled solutions. Fabrication is also addressed to highlight main challenges associated to assembling and welding clad and lined pipelines.
In this paper the key aspects of the design and qualification are presented. Due to sour and CO2 service requirements for the production and water injection risers, it was decided to use corrosion resistant alloy (CRA) mechanically lined pipe for the entire line, with the exception of the top and touch down sections, where metallurgical clad pipe was used. Considering its novelty, a significant amount of qualification and testing was demanded. Among the technological innovations part of the SCR package is the first successful application of a pressurized mechanically lined pipe by reel-lay method. The solution involved an extensive qualification program, including full scale tests on vessel. The methodology and rationale to allow the application of high strain levels during spooling mitigating potential risk of wrinkling within the internal liner, had to be addressed during the detailed design by extensive Finite Element Analysis and validation tests.
The SCR itself, due to de-coupling of motions by the buoy, have negligible dynamic response from vessel motions, thereby behaving almost like a static system with robust fatigue performance. The only meaningful fatigue in SCRs is due to current induced VIV and is mitigated using strakes. There was negligible potential clashing with adjacent SCRs.
This paper provides a summary of design and qualification work carried for SCRs lined pipes installed in the BSR system and a discussion regarding main outcomes.
Real Time Monitoring of Oil Based Mud, Spacer Fluid and Piezoresistive Smart Cement to Verify the Oil Well Drilling and Cementing Operation Using Model Tests
Authors: Vipulanandan C. , Ramanathan P. , Ali K. , Basirat B. , Farzam H. , Head W. J. , Pappas J. M. 
Published: April 2015

Abstract
Well control operations are critical to ensure successful cementing of the oil wells with any losses. With increased drilling depths for production of oil and gas there are greater challenges due changes in the natural geological formations with in situ pressure and temperature conditions. Recent case studies on oil well failures have clearly identified cementing and drilling mud contamination as some of the issues that resulted in various types of delays in the cementing operations. For a successful cementing operation, it is critical to monitor the drilling and cementing operation during the installation so that necessary remediation can be made to minimize the delays and losses of cement. At present there is no technology available to monitor cementing operations without using buried sensors within the cement sheath and also monitor the movement of the drilling mud and spacer fluid to determine the changes real time during the installation of oil or gas wells.
In this study, small well models were designed, built, and used to demonstrate the concept of real time monitoring of the flow of smart drilling mud, space fluid and smart cement and hardening of the cement in place. Also, a new method has been developed to measure the electrical resistivity of the materials using the two probe method. Using the new concept, it has been proven that resistivity dominates the behavior of drilling mud and smart cement. LCR meters (measures the inductance (L), capacitance (C) and resistance (R)) were used at 300 kHz frequency to measure the changes in resistance. Several laboratory scale model tests have been performed using instrumented casing with wires and thermocouples. When the drilling mud was in the model borehole the measured resistance was the highest based on the high resistivity of the drilling mud. Notable reduction in electrical resistance was observed with the flow of spacer fluid and cement. Change in the resistance of hardened cement has been continuously monitored up to about 100 days. Also, a method to predict the changes in electrical resistance of the hardening cement outside the casing (Electrical Resistance Model – ERM) with time has been developed. The ERM predicted the changes in the electrical resistances of the hardening cement outside the cemented casing very well. In addition, the pressure testing showed the piezoresistive response of the hardened smart cement.
Calculation Method of Three-Dimensional Fracture Pressure in Shallow Layers of Deepwater
Authors: Deng Song , Fan Honghai , Ji Rongyi , Zhou Yuyang , Shen Weige , Gao Yuan , Han Fuxin , Dai Rui 
Published: April 2015

Abstract
Fracturing pressure is a key index to characterize the formation characteristics, and it is also a basic factor to determine well structure and safety. Furthermore, accurate calculation of formation fracture pressure is of great significance to determine the safe density window of drilling fluid precisely. Deepwater shallow nature is changeable due to shallow flow, shallow gas and other natural disasters. Despite the accurate calculation of the shale formation fracture pressure through computational model, the existing methods still exists some deficiency such as the lack of pertinence and intuitive of special layers.
This paper proposes a computational method of 3-D fracture pressure. Firstly, it calculates single point of fracture pressure in deepwater shallow layers by lateral pressure coefficient method which is more adaptable to the actual engineering. Then 3-D density data and 3-D velocity data can be worked out reasonably based on logging constrained seismic inversion technique by using the Jason inversion software. Besides, it uses the Kriging interpolation method by combining inversion density data and inversion velocity data to calculate pressure of each stratum. Finally, 3-D fracture pressure can be obtained by applying interpolation technique again. After that, it designs the formation fracture pressure software for display,
This paper presents a case study of Yingqiong basin in South China Sea. First, it uses constrained inversion to get 3-D density data and 3-D velocity data, and then obtains the 3-D fracture pressure through the method based on the 3-D seismic data collected. It can conclude the spatial distribution characteristics of the 3-D fracture pressure of the shallow region. And the value of the region has been compared with the drilled wells fracture pressure gradient measured values sub regionally.
Through the comparison and analysis of the measured value, this method effectively improves the calculation precision of 3D fracture pressure. It can be applied in the engineering design to improve the engineering safety, thus it can be widely promoted.
Steel Catenary Risers (SCRs): From Design to Installation of the First Reel CRA Lined Pipes. Part II: Fabrication and Installation
Authors: Maneschy Ricardo , Romanelli Bruno , Butterworth Christopher , Pedrosa José , Escudero Carlos , Vargas Tomaz 
Published: April 2015

Abstract
As part of the ultra-deepwater field development of the Santos Basin, 300km offshore the Brazilian coast, the Sapinhoá and Lula NE pioneering riser system was successfully installed by Subsea 7, acting as a contractor for Petrobras and partners (BG E&P Brasil and Repsol Sinopec Brasil, in Sapinhoá Field, BG E&P Brasil and Petrogal Brasil, in Lula NE Field). The full Engineering, Procurement, Installation and Commissioning (EPIC) project scope comprises the design, fabrication and installation of 4 buoys of 2800 tons moored 250m subsurface, of which 2 connect to the Floating Production, Storage and Offloading unit (FPSO) Cidade de São Paulo and 2 to the FPSO Cidade de Paraty; 27 Steel Catenary Risers (SCRs) with 3.9km each, 27 Pipeline End Terminations (PLETs) and anchorage suction piles at 2140m water depth.
This Buoy Supporting Risers (BSR) system concept presents several advantages to overcome the challenges of installing SCRs on ultra-deep waters, such as, allowing decoupling between installation of risers and the production unit, reducing payload on the unit, reduced risks associated with clashes and very small dynamics transmitted from production unit to the risers, resulting in significant less fatigue issues.
Due to sour and CO2 service requirements for the production and water injection risers, it was decided to use mechanically lined pipe for the entire line, with the exception of the top and touch down sections, where metallurgical clad (metclad) pipe was used. Consequently, a significant amount of qualification, testing and inspection associated to welding lined and metclad pipes was required.
In order to install Corrosion Resistant Alloys (CRA) lined pipes with a Reel-Lay vessel, a novel methodology for water pressurized spooling and pipelay was developed to mitigate the risk of liner damage during installation. Full-scale pressurized spooling trials were done ahead of the pipelay campaign for testing and validation of this methodology. In addition, analyses were performed to evaluate the BSR system behaviour during SCRs installation and to minimize buoy de-ballasting interventions.
This paper describes the faced challenges and solutions engineered in the steel catenary risers' fabrication and installation scopes.
Well Construction Challenges in the Pre-Salt Development Projects
Authors: Pinheiro R.S. , Santos A.R. , Marques M. , Schnitzler E. , Signorini D. , Tomita R.A. 
Published: April 2015

Abstract
The ambitious plan to develop and produce the prolific Pre-Salt reservoirs in the Brazilian Santos Basin was kicked off by the discovery of the gigantic Lula Field in 2006 (previously known as "Tupi"). For Petrobras, the first decade of this century was therefore marked by the significant challenges imposed by these complex carbonate reservoirs, requiring the accelerated introduction of new technologies and innovative approaches to well construction.
This article describes the history of well construction in the offshore Brazilian Pre Salt area. It summarizes the evolution in well design that resulted from the implementation of innumerable "lessons learned" that were acquired since drilling of the first wildcat well in the Pre-Salt Cluster.
The commulative experience of more than 100 wells drilled and 29 wells completed (to date), has resulted in a progressive reductions of time and CAPEX required for the construction of the development wells in the Santos Basin.
Reservoir Characteristics Interpretation by Using Down-Hole Specific Energy With Down-Hole Torque and Drag
Authors: Laosripaiboon Lertsak , Saiwan Chintana , Prurapark Ruktai 
Published: April 2015

Abstract
The cost reduction has become the most challenge in oil and gas exploration. Many technologies have been developed to optimize the drilling and completion operation. One of the solutions is to reduce the cost of perforation. Although, well logging, neutron porosity, resistivity and gamma ray, can indicate the suitable zone for perforation, there still have some perforated zones which cannot be the production zones due to insufficient pressure of reservoir for the production. Thus, the more accurate decision chosen for the perforated zone will reduce well completion cost.
Specific energy is referred to work input to drill a volume of rock and also used to determine the drilling efficiency by comparing with confined compressive strength (CCS). For the perfect drilling operation, down-hole specific energy should be equal to CCS. One of the parameters, which lead the fluctuation in down-hole specific energy is inlet pressure from reservoir. The zone which has higher down-hole specific energy than other zones at the same lithology will have a drilling problem. Thus, the zone which can be the reservoir from well logging data with drilling problems is possible a potential production zone.
The combination of results from the down-hole specific energy and the well logging data can bring more accurate decision in choosing the perforated zone by avoiding the low potential zone. However, a down-hole specific energy calculation needs down-hole torque (DTOR) and weight on bit (DWOB) data, which requires additional budget for measurement using the commercial sensor, thus the friction calculation is preferred to save the budget. In this research, the friction analysis will base on Aadnoy et al [1] and Hareland et al [4] models was used to calculate DWOB.
The assumption of down-hole specific energy was verified using data from two wells in Thailand to calculate the potential zone. The results showed the zone which have been chosen from both of logging and down-hole specific energy can be the production zone and the zone which only chosen from logging data may be a non-potential zone.
Integrated Geohazards Assessments offshore Azerbaijan, Caspian Sea
Authors: Unterseh S. , Contet J. 
Published: April 2015

Abstract
The aim of this paper is to present the methodology implemented to assess the geohazards potentially affecting a subsea development offshore Azerbaijan and the main findings. The site investigated is located on the continental slope of the Caspian Sea in water depths ranging from 50m to 600m.
A preliminary geohazards assessment has been made from the available 3D exploration seismic and revealed large scale geological features, including a giant mud volcano, regional scale Mass Transport Complexes (MTC) and a large slope failure scar at seabed. Nevertheless, the resolution of the 3D dataset was of insufficient quality to address the drilling hazards with enough confidence and a serie of high resolution geophysical site investigations has been recommended. They include a dense 2D high resolution seismic survey and a high resolution Autonomous Underwater Vehicle (AUV) survey, aiming at characterizing seabed and near-seabed geohazards. These geophysical site investigations have been complemented by a dedicated geotechnical survey in order to provide preliminary geo-mechanical parameters and to build a proper geological model. All these surveys have been achieved very early in the development project in order to have sufficient flexibility to adapt the intended subsea field layout and to minimize the exposure to geohazards.
The high resolution dataset revealed an unsuspected complexity in the recent shallow geological history of the site, resulting from the close interaction of tectonics, mud volcanism, high sedimentation rates, mass transport deposits and gaseous fluid upward migration. The gaseous fluid migration is currently active and is at the origin of many geohazards, with gas accumulation at shallow depths, seepages at seabed along faults, mud volcano and pockmarks, and with occurrence of methane derived authigenic carbonates (MDAC). The gaseous fluid migration and accumulation may also be related to the occurrence of slope failures observed at shallow depths within the soil.
Sand Production in Sand Controlled Completions and Topside Wall Loss Assessment
Authors: Huebner Ben , Redpath Wendy , Riley Sean , Joshi Nikhil 
Published: April 2015

Abstract
The most frequent completion method used in deepwater Gulf of Mexico is the use of gravel pack with sand screens. These are used to minimize and possibly avoid any sand production in the production system. Sand production from subsea wells tied back to a host can be a significant detriment to the integrity of the subsea infrastructure as well as the processing facilities at the host location. Hence, it is important to have effective sand control measures as well as reliable methods to measure sand, if produced.
This paper discusses three case studies where sand production occurred even with sand control measures in place. The discussion is focused on the challenges associated with detection and quantification of produced sand as well as its impact on the subsea and topside infrastructure. The cases are for a dry gas well, a gas condensate well, and a black oil well. All three cases are subsea tie-backs to different host facilities.
In these cases, the sand detection methods used are intrusive and acoustic type sand detectors, as well as centrifuge measurements of the produced fluids. The challenges associated with these methods are discussed in this paper. It is concluded that, at least in one instance, the acoustic device is reliable in identification of sand production but unreliable for quantification of the sand volume.
In addition to produced sand measurements, inspection measurements which indicate wall loss of piping at the arrival of the fluids to the host facility are discussed. An attempt has been made to correlate the wall loss from inspection with erosional model predictions. It is concluded that the uncertainty in measured data is significant and, to pursue such a correlation, improvement in sensor reliability as well as accurate sand production data is required.
Examples of Broadband Processing and its Effect on Amplitude Versus Offset (AVO) Products
Authors: Laha Sampad , Casady Mark 
Published: April 2015

Abstract
Presence of ghosts in conventional marine seismic images reduces imaging resolution and bandwidth of the data. Removing these ghosts can increase the resolution of the data and make the data broadband resulting in a better image. We use a broadband processing technique to achieve this. This technique is applicable to marine acquisition, including conventionally acquired datasets. In this paper, we present various broadband examples from different parts of the world to probe the imaging enhancement. Broadband processing has enormous potential for increasing resolution, and thus adding value to seismic data. However, few studies have been performed on AVO analysis of broadband processed data. This paper also examines the AVO aspect to demonstrate the effect of broadband processing on AVO and its attributes.