Nitrogen Vs Compressed Air in Coiled Tubing Operations, An Affordable Safety Practice?

Compressed air is most often used with coiled tubing operations. Well depth and whether there are likely to be liquid hydrocarbons in the well are key factors in determining whether compressed air is safe, or if there is a likelihood of a downhole explosion/ignition. One service company goes so far as telling employees not to use compressed air if there will be liquid hydrocarbons in the well. And there's usually no liquid hydrocarbons in shallower low-pressure gas wells. Go deeper though, below 2,500 ft, and there may well be liquid hydrocarbons with rich gas. One service company noted that industry has been experiencing more minute downhole "flashes" in recent years with the introduction of higher-pressure air compressors. Risks are increasing with greater air-gas ratios. Consensus on maximum bottomhole pressure for safe usage of compressed air is needed. 

Cost is most often cited as a major disadvantage of using nitrogen. But higher cost is partially offset by nitrogen's higher lifting ability, and the higher volumes achievable with nitrogen pumpers, more than double compressed air, can be a factor favoring nitrogen. To reduce cost, nitrogen vendors are working on pumper design. To increase their efficiency, non-fired heat recovery systems (from truck exhaust and coolant systems) are being employed to reduce or eliminate burners. Beyond efficiency gains, pumper units with non-fired heat recovery systems are more environmentally friendly. In the end, the nitrogen versus compressed air decision must balance cost and safety considerations. Philosophically, companies are reacting positively to using more nitrogen at reasonable prices while providing more safety. 

Excerpted from article in Drilling Contractor, March/April 2003, 
p. 4.

Health, Safety & Environmental Planning Guidelines for Underbalanced Operations

The Health, Safety and Training Subcommittee of IADC's (International Association of Drilling Contractors) Underbalanced Operations Committee recently completed a draft document of HSE Planning  guidelines. The draft guidelines are intended for use by integrated project teams involved in underbalanced drilling operations. 

The guidelines, which are applicable both onshore and offshore, provide information and guidance on HSE-related activities during the planning phase that will  have an impact on safety during the execution stage. Not intended to replace existing company safety policies, the guidelines should be considered as a starting point for developing safety management plans.

Excerpted from an article in Drilling Contractor, March/April 2003, p. 24. The draft guidelines are available online through IADC's website (www.iadc.org/committees/
underbalanced/Draft
documents.html).

DOE's Rocky Mountain Oilfield Testing Center (RMOTC) in Casper implements projects with a definite environmental flair, in addition to projects that field test technologies. Four such projects, each outlined in their recent newsletter (www.rmotc
.com/Today/Newsletter.html), are summarized below.

Regional Carbon Sequestration Partnership. RMOTC is part of a newly formed Rocky Mountain Regional Consortium of academic, industrial, governmental and non-profit organizations that are investigating the capture, storage and overall reduction of greenhouse gases. Potential carbon sinks in the Rocky Mountain region are both geological and terrestrial. Potential geological sinks include nearly depleted oil and gas fields, saline aquifers and extensive unmineable coal seams. In the near term, sequestration of CO2 in terrestrial ecosystems, such as high altitude pine forests, offers a low-cost means of reducing net carbon emissions. For more information about the Consortium, contact Vicki Stamp, RMOTC (Vicki.Stamp@rmotc.
doe.gov). 

Wetlands-Treated Produced Water. RMOTC, Chevron Texaco and Clemson University are conducting a three-year project testing constructed wetlands-treated produced water for beneficial reuse. Both RMOTC and Clemson will construct pilot wetlands to remove hydrocarbons and salts from produced water. As water is released from the constructed wetlands, studies will be performed to identify the viability of using treated water in beneficial applications. Among other things, growth rates of vegetation in treated water will be compared with those using standard irrigation water. Workshops presenting results are planned. For more information, contact Lorri Jackson, RMOTC (Lorri.Jackson@
rmotc .doe.gov). 

Ice Cleaning System for O&G Field Operations. The Ice Cleaning System, which converts water into small ice particles that are pressured

 through a hose-nozzle system to clean surfaces, is environmentally attractive since it generates a minimal amount of residual waste. Performance in an oilfield environment was documented in a RMOTC field test (www.rmotc.
com/pdfs/IceCleanSystems.
pdf). The Coast Guard in Alabama has since successfully demonstrated the system for maintaining navigational buoys. 

The demonstration confirmed that the equipment could be carried on board the tender vessel and buoy maintenance performed at sea. For more information on the various applications of the Ice Cleaning System, contact Lorri Jackson, RMOTC (lorri.Jackson
@rmotc.doe.gov).

Dust Control in Powder River Basin CBM Operations. As part of a coalbed methane research program at RMOTC, staff members have identified dust from unpaved roads as possibly a significant impediment to planned developments in the Powder River Basin. They are working with other technical experts and county road engineers to develop Best Management Practices (BMPs) for constructing and maintaining unpaved rural roads within regulatory limits for airborne particulates. For more information about this and other aspects of the CBM program, contact Jim States, RMOTC (Jim.States@rmotc.
doe.gov).

Drilling, Well Servicing Training at San Juan College, New Mexico

The U.S. Department of Labor (DOL) recently announced an award to San Juan College, Farmington, New Mexico, to support the development of an energy-based Business and Industrial Training Center. The $2.17 million grant will be used to fund petroleum technology training and placement programs to support industry needs in New Mexico and the adjacent Four Corners area. The programs will provide education, training and job-placement assistance involving non-traditional classroom for hands-on training on actual equipment, including a workover rig donated by Key Energy Services. The programs are expected to lead to 300 full-time jobs.

Technical training will be provided in industrial safety, drilling and well service, gas compression technician skills, plant operations, commercial driving skills and heavy equipment operation. It will also offer short-term fast track job training, one-year certification programs and employment assistance. This effort is part of the President's comprehensive plan to ensure that the nation has the energy - and the energy workers - it needs.

Excerpted from article in Drilling Contractor, March/April 2003, 
p. 4.