3. Read the text “Companies” and do the exercises. Companies

The companies include operating companies, drilling contractors, and service and supply companies.

Operating company

An operating company, or an operator, has the right to drill and produce petroleum at a particular site. The operator buys or leases that right from the owner of the rights to the subterranean oil or gas. Rights can be owned by individuals, companies, or, in some cases, by the federal or state government.

An operator can be a major, such as Exxon, Mobil, British Petroleum, Shell, Chevron, or Texaco. A major oil company produces oil and gas and transports them from the field to the refinery and plant. It also refines or processes the oil and gas and sells the products to consumers.

An operator can also be an independent. An independent operator is an individual or a relatively small company that produces and sells, oil and gas but does not transport, refine, or market them. Operating companies, whether major or independent, pay for the drilling of a well. They usually hire a drilling contractor to drill it.

Drilling contractors

In the United States and Canada, drilling contractors do virtually all the drilling. Operators have found it more cost-effective to hire a firm that specializes, in drilling than to maintain their own rigs. A drilling company may be small or large; it may drill mainly in one country or it may have rigs working all over the world.

In any case, a drilling company's job is to drill a hole. It must drill the hole to the depth and specifications set by the operating company. An operating company usually bids up several contractors. Often, the operator awards the contract to the lowest bidder, but not always. Sometimes a good work record may override a lower bid.

Service and supply companies

The drilling of any well involves several service and supply companies. Supply companies sell expendable equipment and materials, such as drill bits and mud, to the operator and drilling contractor. They also sell items such as pipes, fuel, lubricants, fire extinguishers, and spare parts. Moreover, they market safety equipment, rig components, paper, water, tools, computers, paint, grease, rags, and solvents. Think of any part or commodity that a rig needs to drill a well, and you'll find a supply company on hand to fill it.

Service companies offer special support to the drilling operation. Like supply companies, they exist to nil the special needs of the drilling project. For example, a mud logging company logs, or monitors, the drilling mud as it returns from the well. The returning mud carries cuttings and any formation fluids, such as gas or oil, to the surface. The operator can gain much knowledge about the formations being drilled by analyzing the returning drilling fluid.

Another kind of service company provides casing crews. A casing crew runs large pipe into the well to line, or case, it . Casing protects formations from contamination and stabilizes the well. After the casing crew runs the casing, another service company— a cementing company—cements the casing in the well. Cement bonds the casing to the hole. In many cases, when a well reaches a formation of interest (usually, a formation that may contain oil or gas), the operator hires a well logging company. The well logging crew runs sophisti­cated tools into the hole. These instru­ments measure and record formation properties. By looking at the record, or well log, the operator can often determine whether the well will produce oil or gas.

(Baker R. “A Primer of Oil Well Drilling”, 2001, Austin, Texas)