Rock engineering issues emanating from underground hydrocarbon storage

The underground stockpiling of hydrocarbon products has been ongoing for quite a while. The security challenges that are included are well archived. The underground stockpiling has ended up being financially savvy when compared with over-the-ground steel tanks. Alternate favorable circumstances that the underground stockpiling has incorporate reduced operation costs, not very many surface area prerequisites, less fire perils, and in addition steadier room temperature which may prompt the decrease in the rate at which energy is devoured.

The routine strategies that are utilized for oil and gas underground storage includes the employments of drained oil and gas reservoirs in fields including rock salt caves and aquifers. The utilization of exhausted oil and gas supplies was all through the US even till around the 1950s. Furthermore, there were around 480 gas storerooms of this type all around the globe that gives around 76 percent of the volume of gas storage in 2008. It is a general idea that the drained oil/gas repositories are not just the widespread strategy for saving natural gas to a high amount; however it is also the most practical choice. The weight as at the season of revelation is the most extreme gas pressure which infers that there is little danger of any gas spillage since the oil and gas was already there before it extraction.

Making utilization of the gas storage in aquifer technique depends on the same idea as that of the drained oil and gas fields. But, there is a requirement for a significant huge quantity of site portrayal in order to guarantee that there are reasonable topographical conditions for the capacity of the gas. Additionally, the capability of the gas spillage from the capacity formation which is as an aftereffect of the new weight slope should be assessed deliberately. Because of this preparatory work that is required to the ability to hold gas under this pressure, this choice is very costly when compared with that of the drained oil/gas repository stockpiling. There are around 80 offices of this kind accessible on earth. Additionally, a large portion of them are situated in the United States, the Soviet Union, furthermore the Western Europe.

Another form of gas storage involves the storage of compacted natural gas in caves that are created from rock salt configuration by leaching; that is done through the injection of fresh water that dissolves the salt layers. Advantages that the storage of gas through this method has are the high injection and withdrawal rate when it is compared with the storage in empty reservoirs and also the aquifers. However, the time need for the construction of this kind of storage option is much longer in comparison with other traditional storage methods.

dingwangltd / September 25, 2016 / Hydrocarbons

Checking The Integrity of Wells With Casing Inspection Specialists

Casing inspection checks the integrity of a casing to find holes, cracks, or any corroded areas there may be in the casing.  It also detects any scale or bacterial buildup there may be.  Casing failure can be caused by deformation, physical wear, or corrosion and can seriously impede well production.  Casing inspections are important to ensure that a well continues to work properly and prolong its life.  Inspections should be done annually and the well owners, in between inspections, should continue to monitor it themselves for any kind of problems that could arise.  You don’t want to experience any loss of capacity or pressure, which means the well might not be producing as much water as it should be.  Casings are hollow steel pipes that are used to line the inside of a wellbore.  Casings, when maintained and kept in good shape, ensure that the well and water are protected and safe.  Casings prevent contamination and provide a foundation for deeper drilling.

There are many different kinds of casings.  Conductor casings, surface casings, intermediate casings, production casings, and production liners.  Ultrasonic imaging tools are used to evaluate external or internal corrosion.  Electromagnetic corrosion and protection tools measure the casings resistance in wells and helps determine the amount of corrosion that is present.  Companies use inspection logs to note these findings.  Two other common techniques used for casing inspection are cased-hole calipers and flux-leakage tools. The log will display any visible holes in the casing as well as any other deformities that are present. Cased-hole calipers determine any changes in the casings diameter which could be a result of damage due to wear and corrosion.  Flux-leakage tools are a magnetic method of testing that detects corrosion and pitting in pipelines.

The log is a record of the casing’s thickness and integrity.  The log will also allow a company to determine the extent of any damage that is present and determine what costs will be involved in making the necessary repairs. Casing Inspection is an integral part of the overall welfare of a well.  Casing is a big cost and the necessary steps should be taken to maintain and protect it and ensure that the well continues to properly function.  Casing inspection logs are vital to tracing mechanical damage and lowering the costs that would be associated with any damage as long as they are regularly maintained.

dingwangltd / August 25, 2016 / Well Logging

Plant Shutdown

How to Mitigate the Effects of a Plant Shutdown

The world over, refineries carry out the crucial role of refining crude oil into gasoline, kerosene, diesel and other assorted petroleum products. There are times that this function is disrupted in a process known as plant shutdown. This occurs for a number of reasons:

  1. The impossibly high prices of crude oil may force the refinery to disrupt its normal operations
  2. Accidental like fires may cause massive damage to the machinery, necessitating a disruption in operations
  3. Natural disasters like earthquakes, typhoons, tornadoes, etc. They may incapacitate the operations of the plant rendering it inoperable.
  4. in accessibility to raw materials that are needed for the operations of the plant may lead to the unplanned disruption of operations in the refinery.

The disruption to the normal operations of the plant will definitely cause an interruption in the supply of the petroleum products to the clients. A firm therefore needs to develop sound strategies to mitigate the effect of the plant shutdown. This is principally because the low supply will directly impact on the price of petroleum products, due to the laws of demand and supply.

How a firm effectively deals with this problem will be influenced by a number of factors. First, a lot of Geo-economic dynamics come into play. A firm that is situated in the US or Europe will experience less down time because of its close proximity to the requisite expertise and materials necessary to resolve the problem. The US firm will find it easier and more convenient to contract Engineers necessary to correct the anomaly, than a firm in West Africa. However, the firms in the Third World may have a marked advantage over their Western Europe or American counterparts when it comes to environmental issues. The American firm would have to abide by stringent safety, health and environmental requirements before the government gives them the nod to resume operations. This may not be the case in Guatemala or Algeria, where the standards may not be so high.

Being unplanned, a plant shutdown can occur at anytime and without notice. However, the loss that may be occasioned by this occurrence can be lessened by the operators anticipating the disruption and taking the following measures:

  1. The firm should conduct a regular inventory of its equipment, paying particular attention to their condition.
  2. The risk profile of the equipment should be done and the appropriate insurance covers arranged.
  3. The company should identify the critical experts that it would call on in case of a shutdown. The firm may consider putting such experts on retainers if it is not too costly.
  4. Identify alternative sources of raw materials – oil and gas.

If the firm invests in a flexible resource pool and is well organized, then a plant shutdown need not cripple its operations.

dingwangltd / July 27, 2016 / Oil & Gas

Control Valve Repair

Control Valve Repair Procedures

The petroleum refining industries holds the most important part in the modern global economy. The industry is constantly in close contact with raw materials that are distilled through columns and pipes, regulated by valves which control the flow, pressure, etc. The finished product is most likely so important, although their market values are rapidly fluctuating, they are still reported every day on television, radio, Internet, and newspapers. Therefore, they have very valuable assets and have to conduct control valve repair once in certain period to make sure that everything goes well without any rooms for errors which could lead to product failure.

It is important to have the control valves checked once in awhile. Control valve repair is also necessary to be done whenever an error or problem is found. This is to make sure that the refinery will keep the proper performance of products. The process of refining itself has many phases from gathering crude oil and other raw materials before it is processed and ready to be used as our daily needs. There are three major control valve repair and maintenance methods which assures the machine will have uninterruptable performances during the processing phase of raw materials.

The first and the basic method is called the reactive maintenance. This maintenance allows slight errors in control valve repair to go unnoticed and untreated, just because there is no clear indication of a problem. Important control valves could be ignored until there is a severe leakage or failure to function. In certain cases, the production team would give feedbacks to the maintenance dept so that they could take action before the condition develop into something more serious. But if there is a suspicion of malfunction among the valves, they might be removed for further inspection and replacement. This process could end in decreasement of productivity and wasting the time of production.

The second method is the predictive maintenance. Besides conducting the maintenance procedures on a control valve in a routine, the person who is in charge for maintenance should have thorough knowledge of the construction and operation of the valve. Without this knowledge, it could result in damaged equipment or injury on the maintenance personnel. The personnel should pay extra attention to the sectional drawing of equipment which has been provided to help understanding the process of the equipment and identifying the parts. Commonly, among all major types of control valves, the actuator produces force to place a movable valve plug, ball, or disk which is related to a stationary seat ring or sealing surface. The movable part should be responding to changes in actuator force. Failure to take enough measurements before maintaining a valve could result in personal injury or equipment damage.

The last is the preventive maintenance. Generally, this represents a significant improvement. However, because they have been able to obtain information on valves that are operating maintenance schedules, many refineries often conduct maintenance of all control valves simply on a rotating schedule. Such method result in repairing some valves that actually don’t need repairing or adjustments and leaving others in the system long after they have stopped operating efficiently.

dingwangltd / July 7, 2016 / Control Valves

Non-Destructive Casing Inspection Specialists

Casing Inspection

If we talk about petroleum refinery and processing, the casing inspection is one of the important factors to be done once in certain period. A casing inspection is the process to observe the integrity of the casing or tubing to find holes, cracks, or corroded spots and fluid entry or exit points that should not be there. This process is also meant to scale bacteria buildup, which can influence the flow of hydrocarbons from the wellbore. Casing inspections is very important, moreover to the industry related to oil and gas, energy, process and chemical sectors. Storage tanks hold the raw materials which is essential to these industries processes and operations, and the material itself often has less than ideal properties, such a high reactivity.

The general method of inspection utilize the field of non destructive testing, so that they can conduct the analysis of the status of the materials, without changing or alter it in any way. The alternative could involve cutting some sections of material to be analysed at a lab. This method could alter the structure and unnecessarily weaken the tank, besides, this is impractical method to inspect the entire area of the container tanks.

Non destructive casing inspection has several methods and levels of tank inspection depending on the thoroughness and level of inspection that is needed for a particular tank or tanks. There is more to the simple inspections, dye penetrant inspection, ultrasonic testing and magnetic particle inspection are all general methods that can usually be done by an NDT technician with certifications in relevant field. These techniques could be tried and tested while more thorough inspections are carried out by inspecting with a schema developed by EEMUA (Engineering Equipment and Material Users Association), such as EEMUA 159, which forms the standards for casing inspection. It is the recommended way to do Inspections which fulfills the standards such as these. In most cases, the inspection is regulated by safety concerns and tight legislation. Inspecting using a standard such as EEMUA 159, will ensure both of these targets are achieved thoroughly.

There is also more approaches using advanced techniques such as electromagnetics. The newer technology that has been used frequently because of its convenience is LFET (Low Frequency Electromagnetic Technique). This method uses electromagnetic coils to generate an electromagnetic field within the container tanks, which then will be disturbed if there is any defects in the material. LFET is a great method due to its ability to rapidly scan areas and distinguish between top and bottom side defects such as during the inspection of a tank floor.

Generally all areas of a tank will need to be inspected, the floor will use a technique such as LFET, the welds uses MPI (Magnetic Particle Inspection), dye penetrant or preferably eddy current testing, which has the ability to inspect linings thoroughly, making it especially useful. The shell will be inspected as well with ultrasonics, and any other components that needs inspection according to the reports. Visual inspections, and the other additional checks and measurements will use EEMUA as the standard like any other inspections.

dingwangltd / June 21, 2016 / Hydrocarbons