bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Drilling and Completion Techniques Used In 10 Years of the Deepwater Marlim Field Development
Authors: Juiniti Ricardo 
Published: October 2008

Abstract
Marlim field, discovered in December 84, with a total area of 132 square Km lays in water depths from 650 to 1,050 meters. First oil came on stream in 1991 with the vertical well 3 MRL 3 RJS at 721 meters of water, after the development of guidelineless subsea hardware as well as other technologies to allow production in deepwater.
The main idea, still in use these days, was to develop the field with simple drilling and completion projects. The water depth, highly friable sandstone and high costs in deepwater drilling and completion were some of the obstacles to be overcome.
During the field development, the better knowledge of the reservoir, as well as other innovative drilling and completion techniques in deepwater, allowed a higher production of the wells.
A total of 129-production and water injection wells either vertical, directional or horizontal will be on stream in Marlim and many lessons were learned along the last ten years. The best practices for drilling and completion were implemented not only in Marlim but also in other offshore developments in Brazil.
This paper will present the drilling and completion techniques used in Marlim field development and show how these techniques contributed for the production increase.
Although the field development is close to the end, new well designs are being studied to be implemented thus confirming the importance of Marlim field as the most important laboratory for deep and ultradeep water development. Moreover future challenges for workovers will be anticipated.

Introduction
Deepwater drilling offshore Brazil started in 1984 when a conventionally moored drillship drilled the well 1 RJS 287 at 501 meters water depth (WD). In the same year, the first dynamic positioning (DP) drillship contracted by Petrobras also started an exploratory campaign in Campos Basin.
The first well drilled by this DP drillship, the 1 RJS 219 A at 853 meters of water stroke oil in December 84. The tests performed in February 85 showed an unconsolidated sandstone reservoir with permeability of 2 Darcies and high gravity oil (ranging between 17-21 API).
Further drilling and appraisal activities confirmed a total area of 132 square Km with oil in place of 9.0 billion barrels. An appropriate name then was given to this discovered giant field: Marlim. (Fig 1)
Other fields named Marlim Sul, Marlim Leste and Voador fields were also discovered during the delimitation period of Marlim field.
The productivity index (PI) of these wells reached up to 300 m3/day/kgf/cm2 and sand production demanded adequate control mechanisms.
By 1989, ten wells had been drilled in the Marlim Complex and the main problems to drill wells in deepwater were being surpassed year after year, but production at such water depth was still challenging.
Several alternatives to exploit Marlim field were analyzed but all of them impaired restrictions.
A Deep Draft Semisubmersible with a Retractable Heave Plate
Authors: Halkyard J. , Chao J. , Abbott P. , Dagleish J. , Banon H. , Thiagarajan K. 
Published: October 2008

Abstract
Gulf of Mexico deep water oil fields present challenges to the offshore industry. Large fields require heavy drilling and production topsides which favor inshore deck installation, hook-up and commissioning in order to reduce time, costs and risks associated with carrying out such operations offshore. Harsh environments require that the motions of the structure be small to allow the use of dry trees and SCRs. A new system, called the DPS 2001, has been developed, which is a deep draft semisubmersible with a retractable heave plate. The system combines the advantages of a semisubmersible with the operational motion advantages of a truss spartype floater. Minimal motions of the DPS 2001 allow the use of dry trees with drilling/workover capability. The truss/heave plate is in a retracted configuration during fabrication and towing; this allows the deck to be stalled and commissioned inshore. The truss/heave plate is lowered and locked at a deep draft after the DPS 2001 is towed to the installation site. Because of the heave plate, the DPS 2001's motions are significantly less than that of conventional semisubmersibles and ship-type hulls.

INTRODUCTION
The DPS 200101 is a floating drilling and production platform designed specifically for oil and gas development in deep water harsh environments. Three different versions of the DPS 2001system are currently being developed by CSO Aker:DPS 2001-4: a fourcolumn version of the system for 8,000 - 10,000 st topsides,DPS 2001-3: a three-column version of the system for 5,000 - 8,000 st topsides, andDPS 2001-5: a five-column version of the system for use with a topsides up to 40,000 st.
A patent is pending for the DPS 2001. The DPS 2001-5was presented at the 2001 DOT conference. The DPS 2001-3will be presented in the near future. The DPS 2001-4is the focus of the present paper. The DPS 2001-4is shown in Fig 1. The upper hull consists of horizontal pontoons and four corner columns and provides buoyancy. The lower hull consists of a heave plate and a truss that supports the heave plate. The heave plate provides large added mass and significantly reduces the platform's motions. The DPS 2001-4is anchored to the sea bottom with a spread mooring system consisting of chains, steel strand or polyester ropes and suction anchors.
The upper hull is similar to a typical semisubmersible hull. The lower truss and heave plate unit is similar to the truss structure employed on truss spars. The system is an integration of proven components and embodies the best features of both a semisubmersible and a truss spar.
The hull and the truss/heave plate unit can be fabricated in a number of yards in Asia or Europe. Upon completing the hull and truss/heave plate, it will be drytransported to the GOM. The hull and truss/heave plate will be in a retracted configuration during fabrication and transportation (Fig 2).
Prediction of the Holding Capacity and Trajectory of Drag Embedment Anchors
Authors: Ruinen Roderick , Degenkamp Gijs 
Published: October 2008

Abstract
The authors have presented a summary of the various methods that are available to determine the holding capacity and trajectory of drag embedment anchors. One of the drawbacks of the methods that are available today is that these are generally only suited for a single type of soil. The authors are currently working on a methodology that will predict the performance of anchors in varying soil conditions. The initial findings and the methodology are presented.

Introduction
Drag embedment anchors are a common method of fixing floating structures to the seabed. Over the years numerous methods have been developed to determine the holding capacity and trajectory of the anchor in the seabed. The most common of these, are the design graphs developed by the various anchor manufacturers. More recent developments are the development of methods which can predict the anchor holding capacity and trajectory based on geotechnical methods.
The prediction of the anchor holding capacity and trajectory can be split into a number of distinct parts, being:The static holding capacity of an anchor penetrated to a certain depth into the seabed, both in cohesive and cohesionless soils.The profile that the mooring line makes in the seabed (the inverse catenary).The kinematic behavior of the anchor and mooring line in the seabed.
To accurately predict the anchor performance, these 3 parts should be combined into a single methodology.
This paper will discuss the various methods that are available to determine the performance of the drag embedment anchor. The design graphs, static holding capacity, mooring line profile and anchor kinematics will be presented in details showing the various methods that have been developed. The final part of the paper will discuss a method that the authors are working on, which in their opinion gives an accurate method of predicting the anchor performance. While the authors have tried to give a complete view of the material that is available, they do not claim that the material presented in this paper is complete.

Design graphs
The most common method of predicting the holding capacity of drag embedment anchors is the use of design graphs. Typically these graphs are shown on double logarithmic scale, with the weight of the anchor on the horizontal axis and the holding capacity of the anchor on the vertical axis. Holding capacity curves are generally presented for sands and soft clays.
The basis of these design graphs for a specific anchor type is the tests performed with a number of small scale anchors (typically up to a weight of 3 metric tons) which have been tested up to the ultimate holding capacity. The ultimate holding capacity being defined as the maximum horizontal steady pull which can be resisted by the anchor at continuous drag. Based on the tests with the small scale anchors, the performance of the larger size anchors has been extrapolated. These design graphs are supplied by the various anchor manufacturers for their specific anchors.
Expandable Liner Hangers: Case Histories
Authors: Moore Melvin J. , Campo Donald B. , Hockaday Joel , Ring Lev 
Published: October 2008

Abstract
Initial liner top integrity is a primary concern for most operators. If the liner top fails routine or regulatory integrity tests, expensive and time-consuming remedial operations increase direct costs for equipment and services. This remediation delays well completion, which ultimately delays revenue generation. These expenses often exceed the initial cost of the liner equipment. Liner top failure continues to challenge the industry despite improvements in integrally run liner top packers, special cements, and cementing pratices. Even newer generation liner top packers, run either integrally with the liner hanger or as a second trip packer, have multiple sealing surfaces that must function under rigorous conditions to achieve liner top isolation.
The expandable liner hanger has been developed and successfully field-tested as an alternative to conventional "cone and slip" liner hangers and liner top isolation packer systems. The expandable liner hanger combines the functions of the liner hanger and the isolation packer into a single component. The expandable liner hanger uses elastomeric "bands" to provide the axial load capacity of a conventional liner hanger and the annular sealing capability of the liner top isolation packer. The expandable liner hanger is expanded hydraulically with the liner running/setting tool assembly. During expansion, the elastomeric bands are compressed into contact with the ID of the supporting/intermediate casing, virtually eliminating the annular space between the liner hanger and the casing.
This paper discusses expandable liner hanger design criteria and testing undertaken to qualify the expandable liner hanger as a reliable liner top isolation system. Initial field installations and the lessons learned are also discussed.

Introduction
The importance of the liner-casing overlap is illustrated by the efforts and expense taken by operators to ensure hydraulic integrity of the overlap. Typical methods of achieving pressure integrity include the following:Cement "squeezes," including a liner top packer as a component of the initial liner hanger settingOne or more "second-trip" liner top isolation packers installed to control gas migration at the liner top
The typical liner top is complex in its design (Fig. 1) and can develop leaks due to a myriad of causes1.
A recent informal survey of several GOM operators revealed that 30 to 50% of pressure seals in overlaps fail. One operator made a concerted effort to improve liner running and cementing procedures. Data gathered over an 18-month period was used to shed light on possible causes of overlap failure by gathering information on liner/casing sizes, types of equipment, overlap length, mud data, annular cross section, equipment, and service suppliers. The study concluded the chances of having a liner overlap seal failure did not depend on any single factor and the chances for an incident were nearly the same regardless of the factors associated with any given well2.
Ferro-Cement as a Material for Offshore structures
Authors: Shah S.P. , Key W.H. 
Published: October 2008

ABSTRACT
To facilitate rational design in this relatively new material, influence of matrix composition and wire mesh properties on static and dynamic strengths of ferro-cement specimens were studied. The possibility of increasing strength-to-weight ratio by substituting foamed lightweight sand for natural sand was also. investigated. Ductility of steel and specific surface of wire mesh appear to be the most important properties influencing cracking behavior and hence the leakage rate. Results suggest that ferro-cement may be a potential material for construction of thin shells such as for boat hulls, of containers for transportation of LNG, and of deep submersibles.

INTRODUCTION
Ferro-cement is a type of reinforced concrete in which the matrix is portland cement mortar and the reinforcement consists primarily of layers of steel wire mesh. Woven or welded cold drawn wire mesh, having a grid from ¼ to 1 in. and wire diameter from 0.02 to 0.06 in., is commonly used. Presently, the most prevalent use of ferro-cement construction is for ½ to 1½ in. thick shells for boat hulls. The most common construction technique for boat hulls employs bent pipes and. rods to define the shape of the hull. Wire meshes are laid over the framework and the mortar is plastered on from both sides.
Ferro-cement has become an increasingly popular building material for boats ever since Nervi in Italy, shortly after World War II, built a 41-ft × 10.5-ft × ½ in. sailing yacht. Since then, ferro-cement boats have spread progressively to England, Australia, New Zealand, Canada and the U. S. Although most of the boats built in these countries are not larger than 80 ft, larger and more varied types of ferro-cement shipping vessels have been built in Russia and Czechoslavakia.
In spite of the increasing interest in ferro-cement, information on which a rational design can be based and from which a suitable comparison with other materials can be made is not available. The purpose of this research was to investigate the impact resistance of ferro-cement plates since impact loading would be critical for many applications of ferrocement in offshore structures. Behavior under uniaxial tension was also studied and related to the performance under impact. The influence of different mortar compositions and yield strength of mesh, as well as changing surface areas of reinforcement were explored. Measurements of crack width and of leakage rate of damaged material were made. It is hoped that information provided here may lead to better utilization and evaluation of ferro-cement for offshore structures such as shipping vessels, buoys, deep submersibles and vessels for transportation of liquid gases.
Dynamic Response Of Offshore Piling
Authors: Ross Hayes E. 
Published: October 2008

Abstract
To perform dynamic analysis of pile supported offshore structures, the manner in which the individual piles interact with the wave and the soil should be understood. A mathematical model was developed to study this dynamic interaction taking into account nonlinear soil resistance properties and geometrical nonlinearity of the pile. The model also provides a means of studying the effects of permanent set in the soil which may occur as the pile oscillates. The effects of selected parameters on the response of a typical pile are analyzed and discussed. In addition to advancing the state-of-the-art in design and analysis 'of offshore structures, the model can also be used to analyze the dynamic response of a marine riser.

Introduction
Many offshore structures are supported by piles driven into the bed of the ocean. Frequently, the critical factor in the design of these structures is the lateral dynamic loading from waves. Knowledge of the interaction between the pile and its water and soil environment is a requisite to accurately compute the response of a pile-supported offshore structure. The research described herein attempted to fill this need by developing an analytical means of predicting the dynamic response of offshore piling.
Although this study was primarily concerned with offshore piling, it will have applications in other areas. For example, the marine riser on an offshore drilling platform, which is subjected to wave action between the platform and the bed of the sea, can be analyzed by this method. A floating rig which extracts core samples or drills for oil may operate in water of considerable depth and its riser may experience high dynamic loads.
To date, considerable effort has been expended in the field of soil-structure interaction, particularly under static loads, and in some cases under dynamic loads. In laterally loaded pile studies the usual approach to the problem has been through experimental analysis, by either prototype or model. Economically, experimental analysis is often undesirable. Another undesirable feature is that the results are usually applicable to only the type of piles tested.
In most analytical studies found in the literature, inherent assumptions usually limit their results to special cases in which the soil and pile behave as linear elastic systems. For some applications, these assumptions may lead to relatively accurate results, while in others they may result in completely erroneous conclusions. At present the uncertainty remains, especially in dynamic analysis.
Since there was a marked absence of information on the dynamic behavior of laterally loaded offshore piling, the primary reason for conducting this study was to advance the state-of-the-art.
DeepStar 10,000-ft Water Depth DDCV Study
Authors: Bhat Shankar U. , Greiner William L. , Barton Dave 
Published: October 2008

Abstract
Deep Draft Caisson Vessels (DDCV) or spars have been used in the Gulf of Mexico in water depths up to 4,800 ft and their use is being considered in ultra-deep waters up to 10,000 ft. A major study sponsored by DeepStar was used to provide a systematic and credible evaluation of DDCV mooring and riser technology alternatives for a challenging 10,000 ft water depth application in the Gulf of Mexico. This paper provides an overview of the DeepStar study objectives, scope and the significant conclusions. A base case DDCV was first developed for 10,000 ft water depth using extensions of current technologies for hull, mooring and risers. Several cost saving alternatives were then considered. These included polyester mooring, composite risers and a high level evaluation of other lightweight risers. A high pressure and high temperature reservoir and a high current environment (HP-HT-HC) were considered. The comprehensive study resulted in a number of significant conclusions.

Introduction
This paper provides an overview of a major study carried out in DeepStar Phase V (Ref. 1). The primary objectives of the study were to assess credible technology alternatives for mooring and top-tensioned production risers (TTRs) for a large ultra-deepwater DDCV, and to quantify the total system incentives for pursuing synthetic moorings and composite production risers.
In addition to the primary scope described above, the study team was also asked to seek industry input and to provide a preliminary assessment of other potential alternate lightweight risers.
The six month study was initiated in October 2001, with Halliburton KBR as the primary contractor. ExxonMobil was the oil company champion and the manager of this study within DeepStar. DeepStar is a research and development consortium of 15 oil and gas companies and about 50 service companies (see www.deepstar.org).
The design basis chosen for the study included the following challenges:A high pressure high temperature fieldA very high current environmentLarge topsides of 40,000 short tons operating weightA significant number of steel catenary risers (13 SCRs and 5 umbilicals).20 top tensioned risers (TTRs). The scope of the study included consideration of several configuration cases listed in Table 1. The initially agreed scope included cases 1, 2 and 3. Cases 1A, 1B, 2A and 3A were added subsequently as the study developed. The scope of the study was comprehensive, including:DDCV hull sizingMooring designGlobal performance calculationsMooring fatigue analysisRiser configuration designProduction/drilling riser clearance assessmentProduction riser strength and fatigue calculationsHull scantling checksHull fabrication, transportation and installation methodsMooring installationCost and schedule estimatesConsideration of other lightweight riser materials Mooring design and mooring fatigue analysis were performed for both steel and polyester mooring systems. Riser clearance and strength, including fatigue, were analyzed for both steel and composite risers.
Monitoring of Offshore Pipes
Authors: Binet Eric , Tuset Paal , Mjøen Stig 
Published: October 2008

Abstract
The lifetime of offshore field developments can be as long as 20 to 30 years. Operators must have continuous focus on their assets throughout the field life. The monitoring of the operational data is therefore a key issue to assess integrity and to ensure a safe and optimal operation of the flexible risers. In co-operation with CorrOcean ASA, Technip-Coflexip has established a Pipe Integrity Management (PIM) system where relevant operational data, monitoring and inspection results are gathered into a database, treated and analyzed.
This paper describes the PIM system recently implemented for Statoil ASA on the Åsgard field (North Sea). We present the database principle and the most relevant operational parameters monitored in operation. The findings of the operational data review are then discussed and compared with risers original design assumptions. Finally the paper presents the benefits to Operator of such a system.

Introduction
Most Operators operate flexible pipes without a dedicated system to follow up the integrity of the flexible pipes. Hence, any evaluation or assessment of the pipe conditions requires substantial collection of original design data, manufacturing data and not least operational data. Experience has shown than the gathering of relevant operational data can be difficult already after some years in service. In addition, especially for long field life (15 to 20 years), the operational conditions may sometimes differ compared to assumed original design basis data. Without a good knowledge of the operational riser history, the flexible riser integrity assessment can become a difficult exercise, leading for example to either operational limitations or even riser change-out, which could have been avoided or delayed if good monitoring data had been available.
Statoil's Åsgard field development consists of three main floating production and storage units linked by 36 flexible risers. The operating conditions are characterized by high temperatures (130 °Celsius design temperature) and high pressures (up 500 bars injection pressure) combined with large gas volumes. Hence, the riser monitoring system is extremely important for a safe and reliable operation of those risers. Statoil decided in 2001 to develop a reliable Pipe Integrity Management (PIM) system with Technip-Coflexip. The PIM ystem is not intended to substitute the Operator's day to day monitoring system, which remains the responsibility of the Operator's organization. The overall objectives of the PIM system can be summarized as follow:A transfer of the relevant operational data from the Operator's database into the PIM must be done regularly to ensure continuous verification and backup of the riser data, and verification of the risers. Annual transfer is chosen for Åsgard. The frequency may be increased if required.