Modern oil and gas operations are expensive, technologically demanding, dangerous and dirty processes involving volatile oil and gases and a host of highly toxic and deadly chemicals, drilling muds and completion fluids. In order to maintain effective exploration and drilling and avoid possible contamination and safety risks, a vital part of any operation involves the specialist cleaning of these chemicals, alongside oil and gas residues from drilling rigs, vessels and equipment.
Tank cleaning forms a large part of this service and is essential in ensuring that drilling and completion fluids remain clean and free of contamination, thus maintaining an effective drilling programme. The cost and complexity of today’s drilling muds and completion fluids requires 100 per cent elimination of contamination. For example, when storage tanks are not clean, drilling operations are stopped, resulting in rig downtime and hundreds of thousands of dollars in unnecessary costs.
As such, the number of dedicated tank cleaning and decommissioning companies in the oil and gas sector has risen sharply over the last two decades. In the following case study we take an in-depth look at one such company’s operations and learn more about modern oil and gas cleaning and decommissioning operations.Case study
TWMA TES provides a wide and diverse spectrum of specialist niche services that can be applied to a variety of common rig issues, ranging from general rig cleaning including specialist tank/vessel cleaning, through to the decommissioning of redundant structures.
This range of services covers all of the modern cleaning requirements in the oil and gas sector. Nearly every stage of oil and gas operations necessitates some form of cleaning, and as such, a modern provider such as TWMA TES must cover a range of areas, including:
TWMA Vessel Healthcare - an innovative managed service 66for the cleaning and vacuum recovery of aqueous wastes and solids from mud pits, column tanks, pontoon tanks, test separators and storage vessels.
The approach is totally tailored to the specific needs of the client and commences with detailed advance project planning using the most innovative and progressive technologies to enhance and compliment existing approaches.
In this service, various methods of tank cleaning to suit design and layout of the tanks and their pipework are offered. For example, tanks with particularly challenging systems might be more suited for the TWMA EzeeJet cleaning system, which has been designed to allow portable automated cleaning heads to operate using a closed loop methodology.
Benefits of this method include ensuring maximum personnel safety by reducing the need for man entry by over 90 per cent, whilst also minimising waste streams generated throughout the cleaning process by cutting the amount of wash water required.
In some pits and vessels where the waste deposits are heavily contaminated, as often seen in mud pits that contain oil-based mud, it is necessary to introduce environmentally friendly chemicals to assist the cleaning process. It is vital that all products used during any such process are fully soluble in water, readily biodegradable, non-flammable, non-toxic and non-corrosive, providing the most environmentally sound solution possible.
TWMA Asset Life Integrity - Ultra High Pressure Surface 66Preparation, known as (UHP), enables water to be used to remove paint or rust scale, and clean and prepare steel surfaces back to bare metal for recoating. UHP removes 100 per cent of any ingrained salts, which ensures the best possible conditions for the application of new coatings. It operates at pressures up to 2500 bar and productivity rates are far higher than conventional methods, while no hazardous waste results from the process. Furthermore, UHP can also be used for cold cutting of redundant steel structures, a process that ensures no risk of flame or spark and is ideal for operating in hazardous zoned areas.
In addition to UHP, High Pressure (HP) Water Jetting/Retro-Jetting is commonly used in the oil and gas industry for cleaning contaminated inter-connecting rig pipe work, including the cleaning and de-scaling of all nominal bore pipe work from ½ inch to 36 inches. The jetting operates at working pressures of up to 1000 bar and can clean caissons, drill pipe, casings, and risers. The HP Retro-Jetting systems are also used to ensure total cleanliness in FRAC (hydraulic fracturing) completion projects, where it is critical that FRAC completion fluids remain totally clean while being pumped through the rig pit system.
TWMA Pit Management - A service line designed to take 66conventional mud pit cleaning a stage further and ensure a step change in safety. TWMA pit management covers innovative technology for cleaning mud pits, innovative technology for waste minimisation, and an innovative approach to providing an engineered best practice solution.
Gavin Halkett, vice president of TWMA TES comments: “TWMA provides a wide range of services and, in effect, is a one-stop-shop to cover all a customer’s requirements. Being able to offer the oil and gas sector a cost-effective, integrated package simplifies logistics and makes the operations side safer. In order to achieve this target our people are trained to the highest levels in environmental and legislative awareness and operate in key locations for the oil and gas industry.”
As with all oil and gas operations, one of the key factors involved in cleaning is the safety of the personnel carrying out the work. Gavin elaborates: “TWMA has invested heavily in developing operations in key locations for the oil and gas industry, and in R&D to ensure that we remain a step ahead of legislative changing requirements and can effectively contribute to improving safety standards.’’
He goes on to explain that one of the biggest changes in recent years in the vessel healthcare offering has been the considerable achievement in cutting the number of man entries to higher risk zones.
“Much of the new technology witnessed in recent years was first introduced in the UK and when it was proven in the field to be effective and cost-efficient, it was gradually accepted across other geographical locations. Using smart methodology to clean tanks, pits and other areas is definitely becoming the preferred way of completing tank cleaning projects throughout the industry. Reduction in the overall volume of chemicals used and far more stringent controls over the type of chemicals used is also high on the agenda. At the moment, we carry out tank cleaning with closed systems that use on average a third of the chemicals used in the past and we are continuing R&D work to reduce that even further.’’
He adds: “An increasing emphasis in the industry is being placed on specialist cleaning services with lower environmental impacts and reduced need for personnel to carry out procedures is an attractive option for existing and potential customers. All companies in the sector are looking to improve the way they work and to reduce any risk at all to their personnel. Using the TWMA TES methodology ensures tank cleaning and additional services can be carried out cost-effectively and in a timely manner.’’
With the industry continuing to develop at a rapid pace and increasingly complex and demanding drilling operations taking place it is inevitable that the requirements for tank and rig cleaning are becoming increasingly complex. As such, Gavin explains that TWMA, as with all companies involved in the demanding cleaning market must continue to invest in developing new and innovative ways of tackling customers’ needs: “Increasing global levels of environmental legislation and an awareness of the importance of having strong safety records means that demand for tank, rig and vessel cleaning products and services will continue to develop’’TWMA TES
TWMA is headquartered in Aberdeen and has additional operations in the UK at East Tullos, Peterhead and Shetland, and internationally in Egypt, Nigeria, Norway, USA, Far East, Dubai and Libya. The company employs around 310 people throughout the world.
For further information please visit: www.twma.co.uk