Ferino, Jan (Centro Sviluppo Materiali SpA) | Fonzo, Andrea (Centro Sviluppo Materiali SpA) | Di Biagio, Massimo (Centro Sviluppo Materiali SpA) | Demofonti, Giuseppe (Centro Sviluppo Materiali SpA) | Spinelli, Carlo Maria (Eni SpA) | Karamanos, Spyros A. (University of Thessaly)
High-pressure pipeline transportation is one of the key technologies to connect remote gas fields and deliver gas at competitive prices to consumer markets. Arctic regions will become more attractive in the near future as large gas resources are located there. Long onshore pipeline systems, characterized by high-strength steels (above API 5L grade X80, i.e., exceeding 555 MPa yield strength) operated at high internal gas pressure (more than 10–12 MPa) in many cases appear to be the most convenient transportation option. This paper highlights the latest follow-up from a long-lasting R&D program launched by Eni, together with industrial/technical partners, on the exploitation of commercially available options with high-grade steels for onshore applications even in harsh environments. The results obtained in this R&D program can be useful even for applications in Arctic onshore or offshore scenarios.
Natural gas has the chance to be one of the most important and strategic fuel sources in the years to come, even if the growth of the renewable source will play a fundamental role in the “next green power energy,” being the “greenest” among fossil fuels. Natural gas represents a continuous and reliable energy source on an economically viable base and a long-term span. Energy industries have analyzed several potential routes for gas exportation from giant midcontinental fields to final “end-user markets” via either pipeline or liquefied natural gas (LNG) ships. To be economically viable, these analyses include constructability and environmental impact evaluations, route optimization, proper material selection, and optimum hydraulic diameter and wall thickness selection, as well as sizing of intermediate gas-compression stations.
High-pressure pipeline transportation is one of the key technologies to connect remote gas fields and to deliver gas at competitive prices to consumer markets. Several independent technical and economical evaluations have shown how natural gas pipeline transportation systems based on:
This solution allows pipeline projects to meet all the requirements and compete on the “gas to market” for distances greater than 1,000 km, even for large-volume transportation. The main economic advantage of high-pressure gas transportation consists of reduced capital expenditure (CAPEX), saving in construction costs, and operational expenditure (OPEX), as a result of a reduced number of intermediate compression stations.
This paper highlights the latest follow-up from a long-lasting R&D program launched by Eni, together with industrial/technical partners, on the exploitation of commercially available options with high-grade steels for onshore application even in harsh environments. The idea was to fill existing gaps in several fields dealing with pipeline integrity, based on an advanced design approach mixed together with “in field” practical requirements.
The qualification of materials in accordance with NACE MR0175/ISO 15156 is commonly performed by subjecting candidate materials to stress corrosion testing under an applied load in either a standard test solution (e.g. NACE solution A or B) or a test environment simulating service conditions. The exposure times for standard NACE solution A or B can vary from a few days up to a month (720 hours), whilst the exposure time for simulated service conditions is typically one month. This is widely accepted in the Oil & Gas industry and supported by good field experience with alloys such as martensitic and duplex stainless steels, suggesting that this duration is sufficient for those materials.
A similar approach has also been employed in the past for precipitation hardening (PH) nickel alloys, which are being increasingly used in the Oil & Gas Industry. However, field failures of some NACE MR0175/ISO 15156 qualified PH nickel alloys have raised questions over the suitability of the exposure times and test methods that were used.
The present work focused on PH nickel alloys exposed to the NACE Level VI and VII environmental conditions described in NACE MR0175/ISO 15156 for up to 1 year exposure time, to evaluate their performance using both ‘conventional’ and ‘accelerated’ testing techniques. The results indicate that the ‘conventional’ qualification methodology might not be suitable to ensure continuous safe operation for the materials investigated even with extended testing periods (up to one year). However, the approach used in the present work was not fully reproducible and needs further improvement.
Natural gas will play a fundamental role in the "next green power energy era" since it is the unique fossil fuel able to assure an environmentally sustainable transition to full renewable sources in an economical way. At the same time, the nearest gas fields to market areas are mostly depleted; therefore, routes from giant mid-continental reservoirs to end users market areas have been analyzed by the energy Majors. Independent technical-economical evaluations have proven that gas pipeline systems based on semitraditional construction techniques and high-strength steel with high operative gas pressure (above 10 MPa) are the only viable options to exploit "stranded gas fields." Usage of high-grade API 5L X80 steel gas pipelines has continuously increased, thus demonstrating a consolidated trend in adopting it as a standard solution for high pressure gas transportation. The largest development "infield applications" are in North America, the United Kingdom, and many Asiatic countries (mostly China and India).
Ferino, Jan (Centro Sviluppo Materiali SpA) | Fonzo, Andrea (Centro Sviluppo Materiali SpA) | Di Biagio, Massimo (Centro Sviluppo Materiali SpA) | Di Biagio, Giuseppe (Centro Sviluppo Materiali SpA) | Karamanos, Spryos A. (University of Thessaly) | Spinelli, Carlo Maria (eni S.p.A)
High pressure pipeline transportation is one of the key technologies to connect remote gas fields and deliver gas at competitive prices to consumption markets. Arctic regions will become more attractive in the near future as large gas resources are located there. Long onshore pipelines systems, characterized by high strength steels (above API 5L X80, i.e. exceeding 555 MPa Yield Strength) operated at high internal gas pressure (more than 10-12 MPa) in many cases appear to be the most convenient transportation option. This paper highlights the latest follow up coming from a long lasting R&D program launched by eni, together with industrial/technical partners, on the exploitation of commercial available options with high grade steels for onshore application even in harsh environments. The results obtained in this R&D program can be useful for applications even for arctic onshore/offshore scenario.
The numerical tool has been validated against experimental data provided by full-scale burst test and laboratory tests. The coupled use of CFD and GASMISC allowed investigating the fluid decompression behavior involved in the pipeline rupture, thus providing a solid base for the fracture propagation assessment in offshore pipelines even where challenging conditions are envisaged (such as deepwater) and/or where non-conventional gas are conveyed, such as supercritical CO 2 .
Scoppio, Lucrezia (Pipe Team srl) | Nice, Perry (Statoil ASA) | Mortali, Giuseppe (Centro Sviluppo Materiali SpA) | Intiso, Luciana (Centro Sviluppo Materiali SpA) | Piccolo, Eugenio Io (Centro Sviluppo Materiali SpA) | Nasvik, Havard (Statoil ASA) | Cassidy, Juanita (Halliburton) | Amaya, Hisashi (Nippon Steel & Sumitomo Metal Corp.)
Completion designs for deep water high pressure wells commonly require corrosion resistant alloy (CRA) tubing grades with minimum specified yield strengths of 125 ksi to resist against high tensile and collapse loads as well as corrosive reservoir fluids. The types of alloys considered for such well designs and corrosive environments are 17%Cr and super duplex stainless steels (UNS(1) S39274).
On completion of these wells the perforated pay zone may require acid stimulation to remove debris and therefore permit unrestricted hydrocarbon flow. Also later in the well life, carbonate scale may deposit in the completion which needs to be removed with a scale dissolver treatment.
A corrosion testing program aimed at evaluating stimulation acid/scale dissolver packages was designed and performed to determine which package(s) were least corrosive and acceptable for use with wells constructed with 17%Cr and super duplex stainless steels tubulars. Corrosion tests were carried out at temperatures between 70 to 130°C. The stimulation acid/scale dissolver packages consisted of 10%HCl, 15%HCl, and %HCl plus 1%HF including corrosion inhibitors and inhibitor intensifiers. The range of applicability and compatibility against the tested alloys was defined.
Fonzo, Andrea (Centro Sviluppo Materiali SpA) | Melis, Giorgio (Centro Sviluppo Materiali SpA) | Darcis, Philippe (Tenaris Tamsa) | Marines-Garcia, Israel (Tenaris Tamsa) | Quintanilla, Hector (Tenaris Tamsa) | Marchesani, Furio (Saipem) | Vitali, Luigino (Saipem)
In-service flaw tolerability of girth welded seamless line pipes produced by Tenaris has been evaluated under actual in-service bi-axial conditions. Laboratory tests involving different test scales have been conducted: from laboratory specimens to full-scale pipe with intentionally machined flaws in the welds and taking into account different flaw material samplings. Different bi-axial loading scenarios have been considered that are representative of strain-based situations in order to reproduce the effective strain around the flaw and replicate the combination of occasional severe tearing and cyclic straining that may occur as a consequence of line shutdowns during entire life. The applicability of engineering critical analysis based on available standard procedures has been discussed as well.
Demofonti, G. (Centro Sviluppo Materiali SpA) | Di Biagio, M. (Centro Sviluppo Materiali SpA) | Fonzo, A. (Centro Sviluppo Materiali SpA) | Lucci, A. (Centro Sviluppo Materiali SpA) | Spinelli, C.M. (eni)
A significant CO2 reduction of emissions from fossil fuel utilization in large industrial emitters (mainly power generation, but also refineries, cement work and steel production plants) down to acceptable levels can be achieved through different options, such as:
Gas transportation over long distances is more and more needed to gather huge natural gas quantity from far fields to final market. Pipelines are often required to cross harsh areas where ground hazards are likely to occur. The need to study the strain-based behavior of pipelines under imposed displacement pushed the development of full-scale testing facilities and numerical/analytical models for buckling prediction. This paper presents a new analytical formulation for the estimate of pipe strain capacity against buckling. Its development has been carried out by taking advantage of an experimental database coming from Eni’s projects.