pipeline materials – What Is Piping: All about Piping Engineering

Types of Pipeline in Oil & Gas Industry Injection lines: Pipelines injecting water/steam/polymer/gas into the wells to improve the lift.Flow lines: Pipelines from the wellhead to the nearest processing facility.Trunk lines / Inter field lines: Pipelines between two processing facilities or from pig trap to pig trap or from block valve station to block valve station.Export lines / Loading lines: From the processing facility to the loading or export point.Transfer lines / Spur lines: Branch line exiting into trunk line or export line.Gathering lines: One or more segments of pipelines forming networks and connected from the wells to processing facilities.Disposal lines: Pipeline which disposes of normally produced water into disposal wells (shallow/deep).Subsea pipelines: Pipelines connecting the offshore production platforms to onshore processing facilities. Pipeline Typical Flow Scheme – Export Crude (Fig. 1) Fig. 1: Figure showing Pipeline Typical Flow Scheme – Export Crude Pipeline Typical Flow Scheme – Export Gas (Fig. 2) Fig. 2: Figure showing Pipeline Typical Flow Scheme – Export Gas Pipeline Typical flow scheme – Offshore (Fig. 3) Fig. 3: Figure showing Pipeline Typical Flow Scheme – Offshore Codes used in Oil & Gas Industries Design and Construction ASME B31.4 – Pipeline Transportation Systems for liquid hydrocarbons and other liquidsASME B31.8 – Gas Transmission and distribution piping systemsISO – 13623 – Petroleum and Natural gas industries Pipeline transportation systemsDNV –F-101 - Offshore Standard for submarine pipeline systems Sour Applications NACE MR-01-75 – Sulphide stress cracking resistant materials for oilfield equipmentISO 15156 – Materials for use in H2S containing environments in oil and gas production Materials API 5L – Specification for line pipeAPI 5LC – Specification for CRA line pipeAPI 5LD – Specification for CRA clad or lined pipeAPI 5LE – Specification for Polyethylene line pipeISO 3183 – Petroleum & Natural gas industries – Steel PipeISO 14692 – Petroleum and Natural gas industries – Glass Reinforced plastic pipingAWWA M – 45 Fiberglass pipe design Pipeline Fittings ISO – 15590 – 1 Pipeline Induction bendsISO – 15590 – 2 Pipeline FittingsISO – 15590 – 3 Pipeline FlangesMSS – SP 75 – Specification for High Test Wrought Butt welding fittingsMSS – SP 44 – Steel Pipeline FlangesASTM A 694 – Steel forgings for high-pressure transmission service Valves API 6D – Pipeline valvesAPI 594 – Check valvesAPI 608 – Metal Ball ValvesAPI 609 – Butterfly valvesISO 14313 – Petroleum & Natural gas industries – Pipeline valves Other Pipeline Components Pig launcher / Pig receiversBarred TeesIsolation JointsPig signallersCorrosion monitoring fittingsShrink sleeves / External coatings / Cathodic protection for buried lines Corrosion Threats in Oil & Gas CO2 Corrosion (Sweet Corrosion) – General metal loss due to the presence of CO2 in the process fluid.H2S Corrosion (Sour Corrosion) – Localized metal cracking and corrosion due to the presence of H2S in the process fluid.Chlorides and Bicarbonates – Cracking in the metal due to the presence of stress and chlorides in the process fluid.Corrosion due to Oxygen – Oxidation and metal loss due to the contact of metal with oxygen in the process fluid.Microbiologically induced corrosion – Bacteria that induces corrosion particularly within H2SErosion (Abrasion) corrosion – Corrosion due to the fluid flow and velocity within the pipe environments.Corrosion (External) Threats in the facilities – External atmospheric corrosion on above-ground lines and corrosion due to soil for buried lines.Corrosion Under Insulation – External corrosion due to water ingress under the insulating materials. Material Selection Process Identify corrosion threatsDefine the corrosion circuitsCalculate the corrosion rate per yearCalculate the Service Life Corrosion (SLC) based on design lifeConsider the materials optionsCarry out the Life Cycle Costing (LCC) – Capex / Opex / InstallReview the materials selection w.r.t design / operating / constructabilityFinally, select the choice materials Corrosion Agents in Oil & Gas Carbon Dioxide – CO2Hydrogen Sulphide – H2SOxygen – O2Chlorides – Cl-Water – H2O Material Options Metals: CS with a corrosion allowanceStainless SteelDuplex Stainless SteelSuper Duplex Stainless Steel Metals + Lining: CS with internally coated FBECS with internal PE liningCRA clad/lined materials Non Metals: Glass Reinforced Epoxy (GRE)Polyethylene (HDPE) Advantages & Disadvantages of Material Options (Fig. 4) Fig. 4: Advantages and Disadvantages of materials Corrosion Control in Oil & Gas Pipeline Chemical Injections Corrosion inhibitor: Basically meant for CS pipelines, forms a layer of film on the surface and protects the core pipe from corrosion attack. Batch injection or continuous Scale Inhibitor: Prevents scale formation in the pipelines by dissolving scale-forming salts Wax inhibitor: Dissolves the wax within the crude Oxygen Scavenger: Reacts and removes oxygen in the fluid Biocide: Destroys the bacteria, algae, and fungi in the process fluid. Coagulant / Antifoam: Normally mixed in the separators to improve mixing and reducing the foam Demulsifier: Prevents emulsion in the multiphase system Dehydration agents: Removes moisture in the gas normally Glycol injection Odorant: Added to the fluid to add smell and detect the leakage Few more Pipeline related useful Resources for You..Underground Piping Stress Analysis Procedure using Caesar IIComparison between Piping and Pipeline EngineeringA Presentation on Pipelines – Material Selection in Oil & Gas IndustryCorrosion Protection for Offshore PipelinesStart up and Commissioning of the Pipeline: An ArticleDESIGN OF CATHODIC PROTECTION FOR DUPLEX STAINLESS STEEL (DSS) PIPELINEAN ARTICLE ON MICRO TUNNELING FOR PIPELINE INSTALLATIONA short presentation on: OFFSHORE PIPELINE SYSTEMS: Part 1Factors Affecting Line Sizing of Piping or Pipeline SystemsFew Job Opportunities for You