Drill Collars

RK Pipe & Supply sells new drill collars and used drill collars from multiple manufacturers. In addition to our selection of new and used drill collars, we also supply a complete line of new and used drill collarsdrill kellysrotary tablesdrill pipeheavy weight drill pipe, and more. When you buy your drill collars from RK Pipe & Supply, you will have peace of mind in knowing you are buying from one of the industry’s leading providers with 30+ years of history serving the oil & gas industry’s drill collar and drilling equipment needs. Please visit our online inventory and contact our sales department to get started on your order.

Steel Drill Collar Design & Development

Drill collars are typically furnished in the sizes and dimensions shown in Table 1. The drill collar sizes listed in Table 1 were adopted in order to provide a full range of collars with improved connections, as replacement for the collars with the various connections specified in previous editions of API Spec. 7.

Mechanical Properties Of Drill Collars

The mechanical properties of drill collars, as manufactured, should not be lower than the minimum values shown in Table 2. The latest edition of API Spec. 7 should be consulted for method and location of tests.

All drill collar bores should be gauged with a drift mandrel 10ft. long. The drift mandrel should have a minimum diameter equal to the specified bore of the drill collar (standard or optional) minus 1/8 inch.

Drill collars with box-and-pin connections are in the sizes and styles stipulated in Table 1 and conform with the requirements of API Spec. 7, Section 9.

The outside diameter typically complies with the tolerances of Table 3.

External Surfaces of Steel Drill Collars

The external surface of “hot rolled, mill finished” drill collars is to be the typical finish of hot rolled steel bars. Surface imperfections may be present and may be removed by grinding. The removal of such imperfections should not result in stock removal in excess of that shown in Table 4.

Steel Drill Collar Weights

Weights – Table 5 contains steel drill collar weights for a wide range of O.D. and I.D. combinations in both API and non- API sizes. Values in the table may be used to provide the basic information required to calculate the weights of drill collar strings. Stress-Relief Features for Drill Collar Connections – Table 6 are API Spec. 7 Connection Stress-Relief Features.

Figure 1
Figure 2
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6

R.K. Pipe sells a wide variety of new and used drilling equipment including tubular products (drill pipedrill collarsheavy weight drill pipe, spiral weight, etc.), pipe handling equipment (rotary tablesbushings and slipselevatorstongskellysblocks, swivels and hooks, etc.), blowout preventersmud pumps, and many other items.  We handle equipment from multiple manufactures including Gardner Denver, National Oilwell Varco, Continental Emsco, Ideco, MKP, BJ, Webb-Wilson, Baash-Ross, Access Oil Tools (AOT), Wooley, DM, Global, and others.  Please check our online inventory for a full list of what R.K. Pipe has in stock.