Not available for division of payroll with Code 5213 “Concrete Construction – NOC – All Operations to Completion” which is applicable to oil or gas well acidizing or cementing at the same job or location.

Code 6235 applies to employers engaged in drilling or redrilling oil or gas wells, and includes erection or dismantling of drilling rigs, formation fracturing, cementing and installation of casing when such operations are performed by employees of the drilling company.  Cleaning or swabbing of a new well that has not yet been completed is included under this classification whether performed by employees of the driller or by a specialist contractor.

Oil or gas well holes are usually drilled using either a cable or rotary-type rig.  The cable rig involves dropping a pointed bit that is attached to a cable repeatedly into a hole until the hole reaches the desired depth.  The rotary rig involves drilling a holt by applying pressure to a drilling stem that has a rotating bit attached to it.  The latter method is used for both vertical drilling, and for directional and horizontal drilling.  Directional drilling is the process of drilling a curved well, in order to reach a target that is not directly beneath the drill site.  Horizontal drilling can make a 90 degree turn in only a few feet to reach less accessible reservoirs.