Everyone can agree that safety has become an integral part of any construction site. We all have the same goal — to come home safely at the end of every day. An active drilling site presents some significant safety hazards. Working around the large equipment on an active site, including drills, excavators and cranes, requires constant attention and training. Traffic on and in the site also poses a very serious potential hazard. A safety plan should be developed in case pockets of natural gas are encountered while drilling. Each drilling contractor, whether water well, geothermal, environmental or horizontal directional, has a detailed safety plan and requires employees to go through regular safety training.
Drilling fluids do not pose the same immediate risks as the large equipment on site. However, safety training and plans should include the handling of drilling fluids. Before the project begins, it is important to choose the ideal products based on the ground conditions. The safety data sheets (SDS) — or material safety data sheets (MSDS) in Canada — should be printed out and put in a binder along with the technical data sheets for the product. The SDS should be reviewed with each employee on site that will be in contact with the drilling fluids.
Safety Data Sheets
For the most part, the various products used on the standard aqueous drilling job will be safe to handle with bare hands for everyday use. That being said, there are exceptions and it is important that workers read and understand the SDS, or safety data sheets, prior to working with any drilling product. The terms “MSDS” and “SDS” are effectively the same, in that they both refer to safety data sheets. In 2012, OSHA transitioned from the older HazCom MSDS format to the new GHS-compliant hazardous materials standards. Over the last few years, U.S. companies have been reformatting their old safety data sheets using these new standards. The GHS standards, or Globally Harmonized System, were designed to bring all safety sheet information into an identical layout with easily comparable information. Many other countries, including Canada, are following suit. This means that, eventually, a worker anywhere in the world can compare SDS sheets written in multiple languages and know that section 13 always refers to disposal information. In an emergency, knowing exactly where to look on an SDS can save time and potentially lives.
The new GHS requirements are, in general, much stricter and workers may notice that the warnings appear far more detailed and urgent than in the past.
There are 16 separate sections, all of which are useful, but some of which are best to read in full. Section 16 at the very end, for example, provides a quick overview of the hazards, giving numerical values for health, flammability and reactivity on a scale from one to four. This is the same information as was provided on the old Workplace Hazardous Materials Information System (WHMIS) four-color diamond label. A value of one here suggests low risk, while a four value suggests extreme danger. A chemical with a rating of three or four should be treated very carefully and understood fully before use.
Other key, worker safety information that one can find on the SDS includes:
- First Aid Measures (Section 4)
- Fire-Fighting Measures (Section 5)
- Accidental Release Measures (Section 6)
- Handling & Storage (Section 7)
- Exposure Controls/Personal Protection (Section 8)
- Stability and Reactivity (Section 10)
- Toxicological Information (Section 11)
Both polymer- and bentonite-based slurries can cause slipping hazards. Indeed, one of the primary functions of any good drilling fluid is its ability to increase lubrication of the drill stem. Lubricants like oil, graphite or even a drilling fluid will increase slippage of one thing against another. This includes your feet against the ground. Of the various drilling fluids commonly encountered, the most slippery are probably ultra-high molecular weight polymers used in foundation drilling or fluids that have been dosed with an emulsion polymer. The emulsion polymer by itself is likely the single most slippery additive we are likely to encounter on a jobsite, and special care should be exercised if any is spilled around moving equipment or in traffic areas. Because water only makes them slicker, one way to increase safety around spills of an emulsion polymer is to liberally scatter sand or crushed rocks over them until a really thorough cleaning job can be performed safely.
In addition to slip hazards, we need to concern ourselves with inhalation of fine dust. Most of the drilling fluids we use, both bentonite and polymer types, are based on adding a dry powder to water. This fine dust can enter our lungs and become lodged in the narrow airways. Normally, our lungs are very good at removing these foreign particles naturally, but there are types of dust which are harder to remove or can cause problems while present in the lungs. It is always recommended that workers wear tight-fitting dust masks when they will be handling these dry-powder products. The best designs have a port to allow exhaling and are rated for p95/n95 or higher. The number refers to the percentage of fine particulates that are screened out while the letter, “P” or “N” refers to whether the mask is oil-fume rated. For most of our basic drilling use, it is not necessary to purchase the oil-grade “P” rated masks.
Skin Contact/Eye Contact
Bentonite in slurry form does not pose much risk for contact and is, in fact, used in any number of topical mud masks, salves and the like. As a dry powder, bentonite will adsorb moisture and oils from one’s skin, causing it to dry out. Bentonite powder in one’s eyes will likewise adsorb moisture from the eyeball, causing irritation and redness, but little lasting damage. Polymers tend to behave similarly, with most of the issues being related to their tendency to suck up moisture. There are, however, many additives that can cause much more damaging effects. A few that we will discuss below can burn skin and cause blindness. Section 7 of the SDS will list appropriate protective equipment and section 4 will list first aid measures that can be taken if there is a reaction after contact.
There are a few, special chemicals that can react with other chemical types and lead to dangerous situations. Before any new additive is introduced to a drilling fluid, one should understand which other ingredients are incompatible. One of the more commonly encountered of these adverse reactions is mixing hypochlorite-type chemicals with acids. It is a common practice to shock-chlorinate water wells prior to pumping. There are also many products designed to oxidize spent polymer drilling fluids on site. Both of these situations typically call for the addition of a chemical called calcium hypochlorite. This material is a dry, yellowish powder that has a strong odor reminding one of a pool. The combination of this chemical, or the liquid sodium form (aka, bleach), with pH reducers, will lead to the immediate formation of greenish chlorine gas. Chlorine gas in high concentrations can be deadly, leading to corrosion and extreme irritation of the eyes and the lungs. Many well rehab chemicals will reduce the pH, including muriatic acid, phosphoric acid and glycolic acid. SAPP is a phosphate dispersant that can do the same.
Another chemical commonly encountered on drill sites is sodium hydroxide, commonly referred to as “caustic.” The word caustic refers to its ability to burn skin. This particular chemical is capable of literally converting the oils in your skin into soap while digesting the skin. Mixing caustic with acids can result in spontaneous boiling, while contact with aluminum metal will produce flammable hydrogen gas. It is highly important that all people using these and any chemicals understand the dangers of incompatible substances. The safety data sheet lists hazardous chemical interactions under Section 10 — Stability and Reactivity.
As we are primarily using aqueous drilling fluids, most of the ingredients we encounter are non-combustible in nature. However, there are three major exceptions to this. First, there are some additives that use mineral oil as a carrier fluid in order to make a powder into a flowable liquid. Liquid PACs are a good example. These products will burn if exposed to high heat or flame. Mineral oil, however, is not volatile enough to be explosive or truly flammable. The second major exception is finely divided powders. Many dry powders, if the particles are small enough, can create combustible conditions. Clouds of organic powders such as guar gum, sawdust or starch can actually burst into balls of fire if exposed to open flame. Always use dusty products in an open-air environment and avoid flames around hoppers. The third major concern with combustible drilling products comes from those that use volatile ingredients. Typically, this relates only to foaming additives that contain high concentrations of alcohol. Most drilling suppliers have chosen to minimize alcohol in their surfactant formulations, but it is best to read the SDS if there is any question.
Accidents on a jobsite can happen quickly, but the majority of accidents are avoidable. Keeping up with the proper training and knowledge, and continually following safety procedures will help ensure every employee goes home safely at the end of the day.
For more Drilling Fluids columns, visit www.thedriller.com/drillingfluids.