Brine Handling and Personal Safety|
Completion fluids containing compounds such as calcium chloride (CaCl2), calcium bromide (CaBr2), and zinc bromide (ZnBr2) are made by dissolving these and other salts in water. The common CBF chemical salts are shown below in Table 45. The Chemical Abstracts Service registration number (CAS), given in the last column, is a universal reference number for each chemical compound.
TABLE 45. CBF Constituents and Chemical Abstracts Service Numbers
Handling of Clear Brine Fluids
The high concentrations of dissolved salts in CBFs impart a strong affinity for water—to the point where they will readily absorb water from the air (hygroscopic). This strong tendency to absorb water is the basis for most of the safety precautions that should be observed when working with any clear brine fluid.
Contact While Handling
There are certain use and handling precautions that should be followed when rig personnel are working with these fluids. Fluid contact with the skin can cause slight irritation and redness upon a short, single exposure. Continued or prolonged exposure can cause superficial to severe burns of the skin. The fluids can also cause potential eye injury if contact occurs. Contact with the eyes can cause moderate to severe irritation to permanent corneal injury.
|Eye protection is mandatory for all personnel working with clear brine fluids.
Heat of Solution
Another aspect of working with clear brine fluids which calls for respect, is that the addition of dry CaCl2 or CaBr2 salt can generate excessive heat of solution. If solid CaCl2 is added too rapidly while preparing an 11.6 lb/gal brine, enough heat can be generated to raise the solution temperature to more than 200°F. Care must be taken to avoid being burned by the hot liquid or equipment.
For weight up applications, it is advisable to perform a pilot test first in order to check the kind of temperature rise that may be expected in the field.
Two circumstances exist where toxic fumes can be released:
- Brines are not flammable, but they can release chlorine and/or bromine gases in fires fueled by other sources, and
- Oxidizers such as calcium hypochlorite, which is commonly used as a polymer breaker, can release chlorine and/or bromine gases under acidic conditions. Chlorine and bromine gases are both heavier than air and will settle into lower or confined spaces and displace all breathable air.
The type and amount of safety apparel recommended will vary with the specific task being performed. However, hard hats, goggles or safety glasses with side shields, rubber gloves, and rubber boots should be the minimum safety apparel worn when working with, or in the vicinity of, clear brine fluids. Safety packages that contain this necessary equipment are available from all of TETRA’s stock points.
Safety Equipment Overview:
- Goggles or safety glasses with side shields will provide eye protection.
- Face shields may be used in conjunction with goggles or safety glasses, but should not be used alone as they are primarily used to protect the face and throat from frontal splashing.
- Safety showers and eyewash stations should be easily accessible to each area of high activity. Portable eyewash units are highly recommended for remote locations.
- Rubber gloves prevent direct contact of any brine fluid with the hands and arms. A popular alternative to these gloves is thin latex gloves that are worn under cotton knobbies.
- Rubber boots should always be worn around brines. The hygroscopic nature of the brines can dehydrate and cause severe shrinkage in leather boots.
- When splashing is likely, such as when tripping pipe, slicker suits are recommended. Extra time should be allowed for completing projects to prevent personnel from overheating. Slickers should be worn properly and should be periodically cleaned.
- Dust masks should be available when mixing dry additives.
- Moisturizing creams can help prevent the loss of moisture to brines when used beforehand and can help replace the oils and moisture that may already have been lost.
Several precautions may be taken at the well site in order to create a safer environment:
- Pipe wipers not only reduce fluid loss when pulling pipe, they also minimize the danger of fluid dripping onto the floor and rig crew.
- Bristle type floor mats should be used wherever the floor may become wet with clear brine fluid.
- All spills should be cleaned with soap and fresh water in order to remove any slippery residue.
Recommendations for Immediate Treatment
The following are recommendations to follow in the event that rig personnel come in contact with a completion fluid:
- If eye contact occurs, irrigate the eyes with flowing water immediately and continuously for at least 15 minutes. Consult with medical personnel as soon as possible.
- In case of contact with the skin, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Consult with medical personnel as soon as possible.
- Wash clothing thoroughly before reuse. Destroy contaminated shoes.
- As fluids can cause slipping hazards on surfaces, sand or other absorbent material should be applied to any fluid spills to reduce the possibility of falls. Once the spilled fluid has been absorbed, the material should be placed in containers for disposal.
- Everyone directly involved with a project should be instructed in the possible hazards of working with clear brine fluids. TETRA’s fluids specialists conduct precompletion safety meetings to review the Job Safety Analysis and inform all personnel of the safety and handling precautions to be taken with these fluids and the need for proper use of safety equipment.