New Workover Rig, Bound for Deep Basin Pay

First thought when you see the above will be, what new technology is coming to the field and where?  This is actually a reprint of an article Well Servicing Magazine published 50 years ago in Well Servicing Magazine (Jan/Feb 1970). I think you will find the article of great historical interest, both as it relates to rig technology today, and for what is happening in the Permian Basin today.


The strong development of deeper and deeper gas and oil pay in the Permian Basin has motivated the development of some truly gigantic equipment.  Drilling rigs, Christmas trees, pipelines and all other operations and equipment have taken on sizes unseen in this area just a few years ago.

Now that the drilling rigs, logging units, and production facilities are up to size and performing their monumental tasks, the industry is awakening to the need for an even larger workover rig to keep the production flowing.  The Machinery Division of Cabot Corporation has tackled the problem and come up with the rig to meet the large demands of the deeper production.

The approach to the problem was simply applying Cabot’s years of experience in engineering, manufacture and field study of rigs for well servicing, workover and drilling.  The concept has always been to combine various components into balanced rigs for the task at hand.

Gale Holiman, West Texas Division salesman for Cabot, had this to say of the new rig.  “This is actually the first portable twin-engine rig to be delivered to the Permian Basin that is designed for workover and drilling in the deep gas and oil pay of such areas as the Delaware Basin.  It’s an API rated 300,000-pound capacity rig that’s portable and safe.”

The twin-engine, 600-HP rig is designed and engineered to handle 300,000 pounds of tubing and pipe safely over a 14-foot cellar.  The derrick is 112 feet high and telescopes for a roadable load.

Power for the rig comes from two Detroit Diesel (GMC) 8v-71N engines (600HP) with Allison CLBT 4460 transmission and Model 600  compound and lower output drive.  The drawworks is a Model 1287 with an effective braking surface of 3,050 square inches.  It has a 22-inch single rotor hydrotarder-brake assist.  The carrier is a 6-axle, Model 600-C.  Road power comes from the same engine used in rig operations.  The rotary table is designed for use at 21-foot levels for easy accommodation of blowout preventers.  Rotary drive is accomplished by propeller shaft, driven with oil bath elevated chain drive in the derrick.

The main feature of the rig that sets it apart from other rigs now trying to work in the deep pay is the substructure that is engineered and designed for safe work over a 14-foot cellar (a size common in the Delaware Basin).  The new Franks rig has the stamina and design to get on location, rig-up fast and get the job done.  “That’s the main thing I like about the rig,” said M. F. Mache, owner of the new rig.  “We’ve been looking for a rig such as this that has the built-in features we most want.  There are rigs at work now that have been “beefed-up” in one place or another to try to meet the severe service these deep pays demand.  This rig, however, has been designed and engineered from the start to handle the big jobs.”  The rig is API ratted at 300,000 pounds.  “That API rating means a lot in terms of safety and ability,” Machen added.  I believe we’ll see operators save themselves considerable money because this rig can work faster with the heavier loads.  Besides all that, it’s very portable; the main rig gets there under its own power and only a minimum number of additional loads are required to specific applications, such as swabbing, deepening, or whatever is called for.”

“Another thing I like about the rig,” Machen added, “is that while it’s designed for the deeper workovers I can handle the lesser depths – 8,000 feet to 15,000 feet – with ease, because it’s so quick and easy to set up.

The first job for the new rig was Well Number 1, Getty Oil’s Laughlin-Straughan Unit, about twelve miles northwest of Ft. Stockton.  The workover involved remedial work on a collar leak at 18,050 feet.  Machen Well Service Company moved in the Franks rig and pulled the production string of 4-inch tubing.  “We were at work almost immediately,” Machen said.  “The portability of the rig exceeded my expectations.”

Horace Poole, Area Superintendent for Getty said, “I am certainly pleased to see a portable rig with this capacity in the area.  This is our only deep well around here, but I think Mr. Machen will find plenty of work with other operators.  It has the capacity demanded by this deep pay.”

After the tubing was pulled Machen’s crew began drilling out the packer at a depth of 10,000 feet.  After this hole was cleared of gypsum accumulation from the point of the collar leak (18,050 feet) to total depth (22,037 feet).  The leak was spanned with a pair of Baker packers and ninety feet of blast joint.  Pay in the Laughlin-Straughan Unit is in the Ellenburger formation from 21,097 feet to 22,037 feet.

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