Wednesday, 17 April 2019

Liquid Penetrant Test

Non-destructive Examination (NDE) refers to those inspection methods, that allow materials to be examined without changing or destroying their usefulness. NDE is a very important part of the quality assurance program. Different NDE methods are employed to ensure that the weld meets design specifications and does not contain defects. The liquid Penetrant test is capable of detecting surface - connecting discontinuities in ferrous and nonferrous alloys. Liquid penetrant tests are used to examine the weld joint surfaces, intermediate checks of individual weld passes and completed welds. PT is commonly employed on stainless steels where magnetic particle examination is not possible. The examiner should recognize that many specifications limit contaminants in the penetrant materials which could adversely affect the weld or parent materials. Most penetrant manufacturers will provide material certifications on the amounts of contaminants such as chlorine, sulfur, and halogens. A limitation of PT is that standard penetrant systems are limited to a maximum of 125°F (52°C) so the weld must be cool which significantly slows down the welding operation. High-temperature penetrant systems can be qualified to extend the temperature envelope. During PT, the test surface is cleaned and coated with a penetrating liquid that seeks surface-connected discontinuities. After the excess surface liquid penetrant is removed, a solvent-based powder suspension (developer) is normally applied by spraying. The liquid in any
discontinuity bleeds out to stain the powder coating. An indication of depth is possible if the Inspector observes and compares the indication bleed out to the opening size visible at the surface. The two general penetrant techniques approved for use include the colour contrast penetrant technique (normally red in colour to contrast with a white background) and the fluorescent penetrant technique, which uses a dye that is visible to ultraviolet light. For sensitivity, fluorescent penetrant techniques may be used to detect fine linear type indications. The examination is performed in a darkened area using a filtered blacklight. Three different penetrant systems are available for use with both of the techniques, they include a. Solvent removable. b. Water washable. c. Post emulsifiable. Compatibility with base metals, welds, and process material should be considered before penetrants are used since they can be difficult to remove completely. Some requirements listed in article6 0f ASME include:
a. Inspection is to be performed in accordance with a procedure (as specified by the referencing code section).
b. Type of penetrant materials to be used.
c. Details for pre-examination cleaning which includes minimum drying time.
d. Dwell time for the penetrant.
e. Details for removing excess penetrant, applying the developer, and time before interpretation.
f. Evaluation of indications in terms of the accepted standards of the referencing code.
g. Post examination cleaning requirements.
h. Minimum surface illumination (visible or blacklight) of the part under examination.

Monday, 8 April 2019

Oil and Natural Gas

Oil and natural gas are strings of carbon and hydrogen formed from the organic material that has been compressed over millions of years. Oil and natural gas are generally referred to as petroleum. They are often found together. If a reservoir i.e an area underground has only gas and no oil, it is called non-associated gas. A reservoir containing both oil and gas is referred to as associated gas. The oil and gas found underground come in different grades or qualities. In an ordinary sense, the quality of oil is described in terms of its sweetness and heaviness. An increase in the amount of sulfur in the oil leads to the sweetness of oil. Oil with less sulfur is sweeter and requires less processing before use, and is, therefore, more valuable. The heaviness of oil refers to its density. The lighter crude oil can be refined and converted into higher value products, such as the gasoline (or petrol) used by car owners. Heavier crude tends to flow slowly and has more unwanted chemicals that must be refined out. A degree-based gravity scale created by API help compares the relative density of various crudes. Light crude is measured above 31.1API while heavy crude measures below 22.3API. Natural gas is a mixture of methane and some other contaminants. On the amount of hydrogen sulfide in the reservoir, it can be described as either sweet or sour. Refined gas, leaving mostly methane, it is called dry gas. Often natural gas is condensed into natural gas liquids, such as propane and butane. The British thermal unit (BTU) is used to measure the energy output of gas. As gas burns cleaner and has a less destructive environmental impact upon use than oil or coal, the challenges associated with storage and transport makes it more expensive. The oil reserves are usually measured in tons or barrels of oil. Production quantities are abbreviated using “bbl” (or barrels of oil per day, bbl/d or bpd). One tonne is somewhere between six and eight barrels of oil.

Reserves and production quantities of gas are measured in cubic meters (m3) or standard cubic feet (scf) The process of getting oil and gas out of the ground begins with exploration and appraisal. The Oil and gas found underground in reservoirs are sealed but connected to other chambers of oil and gas underground. On identifying a reserve of oil is, the company's often produce a description of the quality of the oil and the estimated amount is measured either by volume (barrels) or by weight (tons) Price fluctuations in oil and gas can impact the direction of the industry because costs are different at different extraction points. Even though the prices are fluctuating, the demand for energy, including oil and gas, is increasing globally. Even though the alternative forms of energy are becoming more popular, there are still strong indications that the use and production of oil and gas will continue. With the increasing industrial energy efficiency, the demand for transportation and increasing population means there is an overall increasing need for energy.

Friday, 29 March 2019

What is meant by Lack of Fusion in welding?

Lack of fusion is the discontinuity in the weld where fusion has not occurred between weld metal and
parent metal or between adjoining weld beads so that we may have lack of side fusion, lack of inter-bead fusion or lack of fusion at the weld root. Incomplete fusion is produced during welding, most often unnoticed by a welder or an operator. After welding, it is most difficult, if not impossible, to detect it by the visual inspection or other non-destructive testing methods. It is most often detected in bend testing of the welded joint when the fracture occurs at the location of lack of fusion in spite of a relatively low load applied. The defect will usually run along the weld interface or individual beads, and thus indicate that there really is lack of fusion.

The main reason for the occurrence of lack of fusion is insufficient energy input at the weld area. Consequently, the parent metal in the weld groove or the previously made beads is not heated up to the melting temperature that is required for the parent metal to mix with the material and make a uniform weld. The lack of fusion is not due to the filler material used but exclusively to improper weld preparation, an unsuitable welding technology, including welding parameters, and weak performance of the qualified procedure. In practice, it has turned out that welders themselves are most often producers of the incomplete fusion. A well- qualified welder will melt the parent metal with an arc, mix it with the filler material, and thus make a weld.

The Operators must use a proper procedure in automatic and robotic welding. An unskilled or, often, the careless welder is bound, for various reasons indicated below, to produce the incomplete fusion in the weld. The lack of fusion can also be called a planar discontinuity of various sizes and shapes. If often happens that only one dimension, i.e. the one in the direction of weld progression, is particularly remarkable There seem to be two causes of lack of fusion, the first being an improper positions of the burner and the second an arc voltage too high, i.e., an arc too long. It can be said that the long arcs in welding with the two wires are the reason for the occurrence of lack of fusion. This statement can be substantiated by the high arc voltage and a very wide weld face. This indicates that the arc energy of the two arcs is distributed over a large area, the energy density is small, and the energy supplied is not sufficient to melt the parent metal. To improve the weld quality the arc length and, consequently, the arc voltage should be reduced and welding parameters should be recorded and stored.

Friday, 1 February 2019

The composition of produced petroleum?

The molecular and atom composition of the  fossil fuel is set by complicated chemical, physical, and biological processes.Generation and expulsion from the supply rocks, is a part of the process because the fossil fuel moves from supply to reservoir, reservoir fill history, and secondary alteration processes  and all influence oil and gas compositions. Every supply facies generates oil with distinct chemical composition that reflects organic phenomenon input, depositional setting, and thermal history . For example, a body of water and coal supply rocks generate waxy, low-sulfur crudes, whereas carbonate and deposit supply rocks generate mineral, high-sulfur crudes. These integrative variations are most apparent throughout the initial stages of oil expulsion and quieten down distinct because the supply issue through catagenes is wherever secondary cracking reactions become prevailing.
Although fossil fuel comes from biological organic matter, most of the individual compounds can't be allotted to a selected organic chemistry precursor. Some fossil fuel hydrocarbons, termed bio-markers, retain enough of their original carbon structure that a possible organic chemistry precursor will be allotted.The abundance and distribution of bio-markers permit geo-chemists to understand  the origin and thermal history of oils. Once generated and expelled from the supply rock, fossil fuel composition will be any changed throughout migration and defense at intervals the reservoir. In most fossil fuel systems, the supply formation is at larger temperature and pressure than the reservoir and migrating fossil fuel fluid might separate into gas and liquid phases that may then migrate severally.Petroleum conjointly interacts with water and also the a lot of soluble hydrocarbons might by selection partition into the binary compound part.Once within the reservoir, secondary processes will alter oil composition. The consumption of hydrocarbons by microorganisms,usually  takes place in the  shallow, cool reservoirs (<80°C).This method by selection removes saturated hydrocarbons, enriching the residual rock oil in polar and mineral material. Bio degradation forms acids and biogenic CH4, CO2, and H2S. microbic alteration of crude oils could be a comparatively quick method and will occur naturally or result from poor production practices. Thermochemical sulphate reduction (TSR) is another reservoir alteration process that may have an effect on oil quality and amount. it's a chemical reaction method that happens at comparatively high temperatures (>120°C), wherever hydrocarbons are  modified to carbonic acid gas and sulphate is reduced to H2S.The petroleum is depleted in saturated hydrocarbons and enriched in sulfur-aromatic species. Reservoir charging and fill history can also alter oil composition.The composition of rock oil that arrives at a works isn't similar to reservoir fluids. Gas and water is separated at the well head and emulsions are broken. Consequently, oil loses some light-weight hydrocarbons (throughout production and transport). Pipeline and tanker oils are a  blend of oils from multiple fields and reservoirs, that on an individual basis could also be of variable composition and quality. Thus  testing of subterraneous fluids from individual reservoirs is important to see field economic science and style reservoir management practices.

The accumulation of economic quantities of fossil fuel (oil and gas) invloves a series of processes  that occur at intervals  at substance basins. Organic-rich sediments are deposited solely beneath specific conditions that promote the assemblage and/or transport of biogenic organic compounds and also the selective preservation of this material. The substance organic matter converts to kerogen, associate degree insoluble molecule with a composition that reflects the organic phenomenon input and chemical alterations (sulfurization, condensation, de functionalization, and aromatization) that occur throughout diagenesis. Once lithofied, these organic-rich strata have the potential to come up with oil and gas once buried and heated to push thermal cracking. Expelled fossil fuel migrates from the supply through fractures and porous strata. Economic reserves occur once earth science conditions yield the buildup, retention, and preservation of great volumes of migrated fossil fuel. 

Friday, 25 January 2019

What comes under Drilling and well operations

Drilling and well operations are at all times be carried out in a safe and prudent manner in accordance with formal plans and requirements. Relevant equipment specifications for operation and maintenance with associated limitations to the extent necessary are reflected in applicable operations and maintenance procedures. Measures are taken to ensure high regularity throughout operations. Exact position of the well and the distance to other wells in the vicinity shall be known at all times. Drilling and Well operation are to be performed with the barriers in place according to the Drilling/Well Operations Program.Operational measures are to be taken to prevent blow-out, fire, explosion, pollution or other damage. Well Control Procedures are been defined and agreed to in advance, and followed accordingly. All drills carried out are to be documented. This relates to the following: • Drilling ∗ Directional Drilling ∗ Casing Running ∗ Drilling Fluid handling ∗ Cementing ∗ Logging • Well Evaluation & Testing • Completion • Start-up & Production ∗ Preparations prior to Perforation ∗ Perforation and Production • Well Intervention ∗ Testing and Maintenance ∗ Wireline, Coiled Tubing, Snubbing Operations Through Tubing ∗ Fluid Operations • Plugging/Abandonment .

It is important that required documentation and certification of the facilities remain valid when demobilisation commences, so as to demonstrate suitability, regulatory compliance and compatibility with required standards. Plans for demobilisation assume prior consultation and concurrence by the operator/owner of the equipment and existing facilities. Any need for safety & emergency systems must be addressed. The specifications for removal and shipment are subject to concurrence by responsible parties by commencement demobilisation. Considerations for simultaneous activities must have to be made. Rigging down equipment and handling for shipment to shore which are not considered as ordinary operations, needs to have a pre-job meeting or a Safe Job Analysis (SJA) with involved personnel by commencement of these jobs (ref. Annex A). Further, the already existing safety requirements must be observed and followed, including any directions given by the offshore installation management .Besides the Operators own assessment of performance has to be done. For the purpose of the continuous improvement and transfer of experience, the Contractor is encouraged to advise the Operator of such matters as: a) Challenges in performance versus set goals for the activity. b) Contractor's suggestions for improvements/simplifications in work processes and methods that might contribute to more efficient/cost effective performance by the Operator and his other contractors for future work. c) Information and feedback from incidents, events, conditions and other matters arising during operations or affecting performance of the services and which have reinforced or changed the contractor's knowledge about specific subjects; or which have resulted in or might lead to changes in Contractor's relevant documentation, methods or work processes. d) Contractor's assessment of deviations from this standard and mandatory requirements, including recommendations for the future. An assessment of measures for reduced fuel/energy demands and steps to reduce the consumption of chemicals and use of chemicals with better environmental characteristics shall be part of the continuous improvement process. The technology that is there for reducing discharges to the sea and emissions to the air are to be continuously evaluated. There has to be some systems in place for handling waste and keeping track of chemicals/substances onboard. Discharges must have to be within the SFT’s regulatory requirements or in the actual discharge permit for the operation. The discharge of drilling fluids and the well stimulation fluids etc. Must be minimised, by reuse of other effort to reduce discharges. All discharges to sea as a results of cementing operations must have to be minimised for both environmental and economical reasons.

Saturday, 19 January 2019

Crude oil distillation

The crude oil distillation systems, with the distillation columns and their heat recovery systems, comes under the first stage of processing in a petroleum refinery. It is an energy intensive process, that consumes fuels at an equivalent of 1% to 2% of the crude oil processed . As the price of energy increases, there must be a reduction in the energy requirement of the crude oil distillation process. At the same time, the environmental problems have resulted in stricter regulations on the emission of green house gases. Consequently, both economic and environmental issues are an important factor in the design of crude oil distillation system. In the crude oil distillation systems, the distillation columns have an interaction with the associated heat recovery systems. In Comparison to the conventional design approach of crude oil distillation systems, the heat-integrated design approach finds a better solution, from which the minimized energy consumption can be obtained. Less energy consumption also means less gas emissions, which is again beneficial for the environment. The heat-integrated design approach is supported by shortcut column models and the pinch analysis method. In order to apply shortcut column models, product specifications in the refineries have to be translated into specifications required by shortcut column models. But there are a lot of limitations present in the existing translation met The crude oil distillation systems contain distillation columns and heat recovery systems (i.e. heat exchanger networks). Usually , the design of distillation columns and the design of heat recovery systems are carried out in a sequential manner. This sequential design approach may miss energy-saving opportunities, and as such several research has been carried out on the heat integrated design approach, which considers the design of distillation columns and their heat recovery systems simultaneously.
The importance of heat-integrated design of crude oil distillation systems has always been a topic of discussion. Several shortcut column models have been applied to develop a heat-integrated design methodology. The reason for using shortcut models is that they are simpler and more robust, compared to rigorous column models .The models and constraints are then incorporated into an optimization framework, that allows the design variables to be optimized in order to minimize the total annualized cost. The major components of the optimization framework are the simulations of crude oil and gas distillation columns and the heat exchanger networks (HEN). In order to optimize the design of crude oil distillation systems, the distillation column and the HEN have to be simulated first. For grassroots design, an initial feasible design is required; while for retrofit design, the existing units are simulated. After the simulations are established, they are then included in the optimization, which aims to minimize the total annualized cost or maximize profit. During the optimization, the column design parameters tend to become adjustable variables, e.g. preheat crude feed temperature, pump-around flow rates; some configuration parameters of the HEN can also become adjustable variables, e.g. adding or removing an exchanger, or re-sequencing an exchanger. The optimization also takes account of constraints such as product quality in terms of boiling points and flow rates and column hydraulic constraints .The reason for adopting shortcut column models is that they are simple and robust, and provides a good preliminary design for the distillation columns. Moreover, applying shortcut column models can allow many important design variables to be optimized simultaneously, which may provide more opportunities to find better design solutions. However, rigorous column models may involve significant convergence problems when many variables are optimized at the same time.

Friday, 11 January 2019

What are the fundamental refinery process and also the products?

Crude oil could be a liquid mixture of hydrocarbons – chemical compounds consisting roughly of six components of carbon and one in all H, each of that are fuels; it usually conjointly carries tiny quantities of sulphur, salts, metals, chemical element and atomic number 7. it had been shaped from organic remains accumulated submarine and eventually cornered in substance rocks these rocks are wherever fossil oil exploration is focused. Usually the oil is compressed, Associate in Nursing gushes out if a pipe is pushed into an productive lure. however because it is extracted, the pressure diminishes, and it s typically unnaturally bolstered by injection of air or water into the reservoir to push up the oil. fossil oil contains hydrocarbons that modify in their boiling point; purification could be a method during which fossil oil is heated in an exceedingly vacuum till it evaporates and so allowed to rise a column. totally {different|completely different} hydrocarbons liquefy at different temperatures and may be collected at numerous heights within the distillation column. within the basic works method, crude is heated to 600ºC by injection of super heated steam and tense in at the underside of a vertical distillation column. because the vapour rises up the column, it cools. The column has trays at numerous heights with holes. because the vapor cools, fractions with completely different boiling points liquefy, collect within the trays and are drained off; product with high boiling points rise to the highest, whereas product with low boiling points collect on lower trays. The principal product, with their approximate boiling points, are crude gas (20ºC), solvent 40ºC), fuel 70ºC), lamp oil and gas jet fuel (120ºC), diesel (200ºC), lubricator 300ºC), and chamber oil (370ºC); solid crude coke collects at the underside when the liquid fractions are removed. 

The proportions during which these product initiate vary to Associate in Nursing extent with the crude; crude is classified as light-weight or significant per the proportion of sunshine product. however the balance of demand and provide for the product is such the costs of chamber oil are abundant under those of sunshine product like fuel, lamp oil and diesel fuel. The principal product obtained from the first purification and cracking processes are (see Appendix - table B5 and C1 for product-wise production and consumption): Liquefied crude gas (LPG), principally a mix of fuel and fuel. it s heavier than air, and liquefies harassed. it s used as a home change of state fuel, refrigerant, and transport fuel four million vehicles are calculable to be high-powered by LPG within the world. fuel is employed to fuel combustion engines principally transport. Its early use as a killer of lice and their eggs has utterly disappeared solvent is employed to form additives for high-octane fuel, and to form compound plastics and carbamide, a chemical element chemical. Aviation rotary engine fuel (ATF) is that the fuel employed in propeller planes it s appreciate fuel. Kerosene, conjointly called paraffin is employed as Associate in Nursing fuel and change of state fuel in Asian country and alternative poor countries, and as an area heating fuel in industrial countries. Jet fuel, employed in jet planes, is closely appreciate lamp oil. High-speed diesel fuel is employed in engines running at 750 revolutions per minute (rpm) or a lot of. it s principally employed in diesel-powered vehicles light-weight diesel fuel is employed in diesel engines running at lower speed – principally irrigation pumps and generation sets. chamber oil is formed by diluting residual oil from purification with middle distillates like diesel fuel. it s employed in boilers, bunkers, heaters, furnaces, or as chemical feed stock Low-sulphur significant stock (LSHS) could be a variant of chamber oil oil consists of greases and viscous oils wont to lubricate moving components in trade, vehicles, railway engines and carriages and marine engines. paraffin is employed as Associate in Nursing electrical nonconductor, for warmth storage and in thermostats. Asphalt could be a black thermoplastic product that s wont to build roads and generally for waterproofing. it s like tar that is formed from coal. Asphalt is additionally found in natural form; it had been wont to waterproof Egyptian mummies. Crude coke is generally used as fuel, however is additionally wont to build electrodes and Leclanche cell batteries. Some petrochemicals are made in massive enough bulk to require a big proportion of works products the globe consumed 345 million plenty of hydrocarbons in 2004 to form 310 million plenty of petrochemicals. Most of the hydrocarbons have 3 intermediates - gas, propane and aromatics – before being born-again to alternative product. Of the latter, plastics accounted for 225 million tons, and fibers for thirty eight million tons; solvents, detergents and artificial rubber accounted for many of the remainder.

Friday, 4 January 2019

What are the new developments in NDT ?

Modern developments altogether areas of technology particularly part, mass transit systems like railways, petrochemicals, oil and gas explorations and process, recreation, bio-materials, industrial and traditional and atomic energy plants, nano materials, micro-electronic parts, composites and multi-layered structures etc. that are enthusiastic about victimization materials that are stronger, lighter, produce other exotic properties and use minimum attainable raw materials. All this is often aimed at increasing the potency, sturdiness and reliability of machines containing parts created from such materials. There are rigorous necessities of managing these exotic new materials and for police investigation and characterizing the very tiny sizes of flaws. Consequently there's an excellent challenge to boost upon the prevailing techniques for non-destructive testing and develop new ones where needed. NDT has continuing to play a significant role for internal control of business product within the extremely aggressive and competitive world markets. It is not going to be entirely out of place to mention that the relative share of a specific country within the world market depends additional and additional on its investment in quality control and quality assurance, that in real terms associate degree in most cases suggests that an investment in NDT.NDT instrumentality has been created additional reliable and sensitive with a trend to form it as freelance of operator errors as attainable. This has seen a bigger use of computers and automation. Usually there is a tendency to see most of the modern NDT with microprocessors and computers with increased capabilities for image processing, knowledge acquisition and analysis. There's a growing trend towards victimization multiple transducers and multi-channel systems each for supersonic and eddy current testing. Equally the conception of simultaneously victimization multiple ways of examination is increasing, for instance for the examination of reactor pressure vessels. 

On-line and continuous watching of plant and instrumentality examination is currently commonly applied. To address the increased use of composite materials high sensitivity check methods like micro-focus radiography and high frequency supersonic testing are currently well established. NDT has been more and more applied in method management as a way to fulfilling the necessity of a good quality assurance conception of creating the product right the primary time. Such a shift towards use of NDT for method management has at the same time demanded development in many connected fields such newer and quicker NDTtechniques, computers and knowledge handling that create it easier to investigate NDT data chop-chop and use it in an exceedingly electrical circuit to switch, management and optimize the method. So there is a tendency to see development of huge installations using machine-driven radiography, tomography, supersonic testing, eddy current testing, and optical-visual testing and infra-red testing. But, increasing the degree of automation conjointly will increase the results of error. Therefore, a high degree of automation needs a high degree of (automated) watching and management. Consequently, a gradual want for machine-driven NDT is ascertained in business. Method integrated NDT has got to fulfill the wants of today’s industrial production regarding integrate-ability, automation, speed, reliability and profitability. A confluence of developments within the fields of physical science, engineering, simulation tools and signal process is contributory to the thrill and fueling a number of the foremost compelling advances. Technology is has added a new life into the sector and there's a lot of to appear forward to during this important scientific endeavor.