Integrity Assessment of Non-Piggable Pipeline Through Direct Assessment

Managing the integrity of pipeline system is the primary goal of every pipeline operator. To ensure the integrity of pipeline system, its health assessment is very important and critical for ensuring safety of environment, human resources and its assets. In long term, managing pipeline integrity is an investment to asset protection which ultimately results in cost saving. Typically, the health assessment to managing the integrity of pipeline system is a function of operational experience and corporate philosophy. There is no single approach that can provide the best solution for all pipeline system. Only a comprehensive, systematic and integrated integrity management program provides the means to improve the safety of pipeline systems. Such programme provides the information for an operator to effectively allocate resources for appropriate prevention, detection and mitigation activities that will result in improved safety and a reduction in the number of incidents. Presently GAIL (INDIA) LTD. is operating & maintaining approximately 10,000Kms of natural gas/RLNG/LPG pipeline and HVJ Pipeline is the largest pipeline network of India which transports more than 50% of total gas being consumed in this country. HVJ pipeline system consists of more than 4500 Kms of pipeline having diameter range from 04” to 48”, which consist of piggable as well as non-piggable pipeline. Though, lengthwise non-piggable pipeline is very less but their importance cannot be ignored in to the totality because of their critical nature. Typically, pipeline with small length & connected to dispatch terminal are non-piggable and these pipelines are used to feed the gas to the consumer. Today pipeline industries are having three different types of inspection techniques available for inspection of the pipeline. 1. Inline inspection 2. Hydrostatic pressure testing 3. Direct assessment (DA) Inline inspection is possible only for piggable pipeline i.e. pipeline with facilities of pig launching & receiving and hydrostatic pressure testing is not possible for the pipeline under continuous operation. Thus we are left with direct assessment method to assess health of the non-piggable pipelines. Basically, direct assessment is a structured multi-step evaluation method to examine and identify the potential problem areas relating to internal corrosion, external corrosion, and stress corrosion cracking using ICDA (Internal Corrosion Direct Assessment), ECDA (External Corrosion Direct Assessment) and SCCDA (Stress Corrosion Direct Assessment). All the above DA is four steps iterative method & consist of following steps; a. Pre assessment b. Indirect assessment c. Direct assessment d. Post assessment Considering the importance of non-piggable pipeline, integrity assessment of following non piggable pipeline has done through direct assessment method. 1. 30 inch dia pipeline of length 0.6 km and handling 18.4 MMSCMD of natural gas 2. 18 inch dia pipeline of length 3.65 km and handling 4.0 MMSCMD of natural gas 3. 12 inch dia pipeline of length 2.08 km and handling 3.4 MMSCMD of natural gas In addition to ICDA, ECDA & SCCDA, Long Range Ultrasonic Thickness (LRUT-a guided wave technology) has also been carried out to detect the metal loss at excavated locations observed by ICDA & ECDA. Direct assessment survey for above pipelines has been conducted and based on the survey; high consequence areas have been identified. All the high consequence area has been excavated and inspected. No appreciable corrosion and thickness loss have observed at any area. However, pipeline segments have been identified which are most vulnerable and may have corrosion in future.

Niobium Microalloyed Line Pipe Steels: Technological Overview

A quantitative understanding of hierarchical evolution of microstructure is essential in order to design the base chemistry and optimize rolling schedules to obtain the morphological microstructure coupled with high density and dispersion of crystallographic high angle boundaries to achieve the target strength and fracture properties in higher grade line pipe steels, microalloyed with niobium. Product-process integration has been the key concept underlying the development of niobium microalloyed line pipe steel technology over the years. The development of HTP technology based on 0.1 wt % Nb and low interstitial was predicated by advances in process metallurgy to control interstitial elements to low levels (C <0.03wt% and N< 0.003wt%), sulfur to ultra-low levels (S<20ppm), as well as in product metallurgy based on advances in basic science aspects of thermo-mechanical rolling and phase transformation of pancaked austenite under accelerated cooling conditions, and toughness properties of heat affected zones in welding of niobium microalloyed line pipes. A historical perspective/technological overview of evolution of HTP for line pipe applications is the focus of this paper in order to highlight the key metallurgical concepts underlying Nb microalloying technology which have paved the way for successful development of higher grade line pipe steels over the years.

Methodology of Risk Management in Pipeline Projects

Organizations of all types and sizes face internal and external factors and influences that make it uncertain whether and when they will achieve their business objectives. The effect this uncertainty has on an organization’s objectives is “RISK”. In recent times all sectors of the economy have shifted focus towards the management of risk as the key to making organizations successful in delivering their objectives while protecting the interests of their stakeholders. Risk may be defined as events or conditions that may occur, and whose occurrence, if it does take place, has a harmful or negative impact on the achievement of the organization’s business objectives. The exposure to the consequences of uncertainty constitutes a risk. Organizations that are most effective and efficient in managing risks to both existing assets and to future growth will, in the long run, outperform those that are less so. Simply put, companies make money by taking intelligent risks and lose money by failing to manage risk intelligently. Risk management is the identification, assessment, and prioritization of risks (defined in ISO 31000 as the effect of uncertainty on objectives, whether positive or negative) followed by coordinated and economical application of resources to minimize, monitor, and control the probability and/or impact of unfortunate events or to maximize the realization of opportunities. Risks can come from uncertainty in financial markets, project failures (at any phase in design, development, production, or sustainment life-cycles), legal liabilities, credit risk, accidents, natural causes and disasters as well as deliberate attack from an adversary, or events of uncertain or unpredictable root-cause. Several risk management standards have been developed including the Project Management Institute, the National Institute of Standards and Technology, actuarial societies, and ISO standards. Methods, definitions and goals vary widely according to whether the risk management method is in the context of project management, security, engineering, industrial processes, financial portfolios, actuarial assessments, or public health and safety. Risk management is a holistic, integrated, structured and disciplined approach to managing risks with the objective of maximizing shareholder’s value. It aligns strategy, processes, people & culture, technology and governance with the purpose of evaluating and managing the uncertainties faced by the organization while creating value. Broadly this paper deals with the objective of risk management along with identification, polarization, mitigation and governance of risks associated with pipeline projects. Further the criteria for assigning the probabilities and impact of an identified risk along with their classification based on its probability and impact are also incorporated in the paper.

Smart Pigging in High Pressure Gas Pipeline Practical Problems and Solutions: A Case Study

Smart pigs, also known as inline inspection (ILI) tools or intelligent pigs, are electronic devices designed to flow on the inside of a gas transmission pipeline, usually while the line is in service, to inspect a pipeline for various types of anomalies that can increase the risks of pipeline failure. This paper describes various problems faced on in service pigging in gas pipelines even after getting data by typical pipeline questionnaire as per NACE RP0102. Problems and solution starting from Launching, crossing SV stations, tap off Point flow tees and Receiving at Pig Receiver including data retrieval from smart pig. First of all, different segment thickness and anomalies of entire length of pipeline will be studied before launch of the tool, because this is important input in ILI tool design in terms of OD and percentage flexibility of pig while run. API 1163 will considered as a master standard for smart pig applications in pipelines. Smart pigging is done once in 10 years interval as per Indian regulation and data recorded in this inspection is important risk assessment input in Pipeline Integrity Management and for deciding life of pipeline. This paper describes various problem faced in pigging i.e. Pig struck before Launching in Launcher, Pig struck at Sectionalization Valve station, Pig stopped in Pipeline without any reason, Pig struck at Flow Tee before Receiver, Pig barrel opening a Hazardous activity, Failure of Data retrieval from smart pig after receiving, Re-run of smart pig and how fluctuating flow rates in different region of pipelines will affect running a pig. This paper deals pig retrieval methods used in different struck ups and various aspects to be considered while planning to run a smart pig. This paper also deals problem faced i.e. magnetized pipe and difficulty in welding after retrieving struck up pigs by hot tapping and stoppling methods and how it was solved. Smart pigging, when properly applied, can serve as a superior inspection tool for many risks of concern over other integrity inspection methods. A proper smart pigging program can play a vital role in integrity management (“IM”) and smooth operation of pipeline without any flow interruption to downstream customers. The downstream customers of different industry which serves to run day to day life of society like Power Plants, City Gas Distribution (CGD) Companies, Refineries, Fertilizers, Ceramics, Dairy units etc will not be interrupted while run a smart pig to avoid consequences and give better service as a Pipeline operator. Smart pig, performance specification shall be qualified by the service provider by any one of the methodologies i.e. verified historical data, Large scale tests from real or artificial anomalies, small scale tests, modeling, and/or analyses. Pipeline operator may ensure final documents and other requirements as per API1163 standards.

Risk and Challenges in Speedy Commencement of Natural Gas Supplies for Last Mile Consumer Connectivity Projects

Over the years the natural gas pipeline industry in India has witnessed significant growth in all three segments namely domestic gas production / gas import, development of pipeline infrastructure for gas transmission and actual usage by end consumers. This is manifested by the fact that in the last five years the gas consumption in the country has increased by over 50 %. Natural gas is the fuel of choice due to controllability and flexibility in use, low emission of CO2 and other pollutants, efficiency in transportation and distribution. Due to this, natural gas the cleanest fossil fuel is emerging as the most sought for fuel across the globe. Last Mile Consumer Connectivity are small pipeline projects that are executed to commence natural gas supplies to prospective customers who come forward to sign firm contractual agreement for commencing gas supplies. These projects are extremely important as the connectivity’s leading to start of commercial supplies by different segments of customers for diversified application generates revenue for the company apart from intensifying economic activities for wealth creation of shareholders. It is experienced that such projects encounters risks and challenges both in the internal and external environment which are either known-known, known-unknown or unknown-unknown. This retards the project progress leading to resource idling. The risks are in different areas related to gas marketing, project execution, operations, economic and regulatory risk. Such risks ultimately affect the company’s net profit, due to delay in commencement of commercial supplies. This in turn retards economic development and wealth creation of shareholders. Efforts has been made to draw and consolidate examples from the experience gained in execution of these projects with respect to the types of risks and challenges being encountered under different phases of value chain, situations, along with measures taken to counter the same. Even though such situations are encountered tactfully leading to successful commencement of gas supplies, the question still remains as to what are the best practices for speedy execution for these projects. The aim of this paper is to provide vivid description and insights into the different types of risks and challenges encountered under the Last Mile Connectivity Value Chain and the best practices adapted for speedy commencement of gas supplies to customers.

Development of API 5L X-80 Plates and Pipes at Essar Steel

India is a large and rapidly growing economy. The energy requirements of the country in terms of oil products and natural gas is also huge. Given its vast geographical size, there is ever-growing need to transport these oil & gas products over large distances but economically. For this purpose, several new projects for laying of new pipeline networks are at different stages of planning. In order to keep the cost of such large pipeline projects lower, countries around the world have shifted to higher strength API grades of steel. This was facilitated by advances in steel-making and processing technology and modern facilities that came up in advanced countries. India is no different and we have seen a gradual shift towards higher strength API grades being used for pipelines. Essar Steel has been a major producer of API grades of steel in India over the last 15 years initially through its hot-strip mill and more recently adding a state-of-the-art 5M wide plate mill as well as pipe mills, both LSAW & HSAW. Different alloy designs have been used around the world to produce high strength and high toughness API grades. These have produced essentially two types of microstructures which are either ferrite + pearlite or ferrite + acicular ferrite. But these microstructures show varying response to the pipe-making process. Choice of alloy design also has a major bearing on the cost of steel, but is partly influenced by mill capability. At Essar, while cost was a major determining criterion for selection of suitable alloy design, mill capability was not a constraint. Essar Steel has successfully produced X-80 plates and pipes with a modified HTP alloy design and using the new facilities of plate mill & pipe mill. The paper gives some of the key highlights of this development activity. This was a collaborative effort between the metallurgists & engineers at Essar Steel India Limited and experts from CBMM.

Managing of a Strategic Crude Oil Pipeline for Maximum Transportation Capacity

The aged crude oil pipeline; 16″ × 166 km since November 1984, extends from Meleiha field at western desert to El-Hamra terminal at coast of the Mediterranean sea. Its original capacity was 100,000 BOPD using two pumping stations; one at Meleiha and the other is a boosting station, 83 km far from Meleiha. Planned pumped flow rate increased to 177,000 BOPD at the time that Maximum Allowable Working Pressure (MAWP) reduced from 1440 psi to 950 psi. This paper shows managing procedures led to pumping higher flow rate without exceeding MAWP, where two solutions to accommodate such increase in production were applied; firstly by looping the existing pipeline with a (16″ × 56 km), secondly by using a Drag Reducing Agent (DRA), so that could reduce hydraulic friction losses and Total Dynamic Pressure (TDP) in the system and could pumped more with reduced initial pumping pressure at Meleiha. So, the intermediate station was temporarily abandoned. Mathematical models are designed to simulate pumping operation through the whole system, where TDP is predicted for the three pipeline cases: 1- normal case without both looping & DRA. 2- case without DRA & with looping. 3- case with both looping & DRA. Laws of hydraulics are applied with the deduced formula represents performance of DRA in which percentage of drop in pressure losses is modeled as a function of DRA dose in ppm. Close agreement is remarked between values of the deduced theoretical values and actual values obtained for TDP, confirming validity of such mathematical models.

Slurry Pipelines: An Economic Solution to Transportation of Minerals and Materials

Slurry pipelines find a special place in industrial applications which require transportation of solid particles through a pipeline. Flow-ability of these solid particles is achieved by mixing and suspending them in water or other carrier fluids. Slurry pipelines are characterized with cost effectiveness for long distances, reliability, low maintenance, low air & noise pollution. Importantly it is eco-friendly and does not affect the environment. Over the past 5 decades, slurry pipelines have proven its effectiveness in cost saving for long distance transportation, safe handling and high reliability. Since the inception of long slurry pipelines in 1957 in Ohio to transport coal, gradually over the period, new technologies in slurry transportation has made it possible to transport minerals and materials over long distances safely and effectively. Many materials such as coal, iron concentrate, phosphate concentrate, copper concentrate, zinc concentrate, lead concentrate, nickel concentrate and limestone have been transported successfully over long distances. The long distance slurry pipelines have certain disadvantages in terms of high initial capital investment, the carrier fluid availability, and importantly it is feasible in areas wherein rail and road transport is not well developed. Most of the mineral concentrates require a beneficiation step that involves grinding of the ore to a very fine size in order to achieve good recovery. This is a wet process and the size of the product is generally suitable for long-distance pipeline transportation. In particular for coal transportation, the drying cost is add-on cost. These all requirements contribute to the transportation cost and make it uneconomical for short distances. Therefore for slurry pipelines to be economic, the distance of transportation will have to be long. In recent times, polyethylene pipes have proven to be very cost effective to transport copper, iron ore, phosphates and gold concentrates. They have high resistance to slurry abrasion, prolonged wear life, high ductility and toughness properties. Pumps are developed to handle high pressures of up to 250 bars and facilitated pumping of solid concentration of 60 to 65% weight. Some alternate carrier fluids result in higher concentrate carrying capacity. Slurry pipelines have proven its high economy and feasibility to operate over long distances. With many developments underway, slurry pipelines will pave way to decrease the load and dependency on rail and roads.

EWPL CP System: A Case Study

Reliance Gas Transportation Infrastructure Limited (RGTIL) is operating its prestigious East-West Gas pipeline (EWPL), since 2008–2009; project comprising of 48” dia. 1375 km long trunk pipeline, with 11 nos of compressor stations and several spur lines of different diameters varying from 10” to 30”. Cathodic Protection (CP) system for buried pipeline, piping and structures is critical for ensuring protection against external corrosion due to environmental interaction. For successful implementation of CP system from day one of pipeline laying; planning and considerations starts at conceptual stage of project itself, then proper planning, design and implementation to follow. Other than considerable length and diameter of pipeline; uniqueness for EWPL CP requirements are in form of 3 nos. Micro-tunnel crossings, 11 nos of Compressor stations (CS) with underground piping, more than 100 cased crossings, several HDD, third-party pipelines, AC & DC Railway traction crossings and pipeline passing through different geography from East to West. Paper discusses the implementation of CP system for EWPL; highlighting critical points for execution of the job in each phase from Engineering till commissioning and O&M, CS CP system, CP for pipe within Micro-tunnelling, several interference and mitigation actions, post-commissioning surveys etc.