1. Field of the Invention
This invention relates to the art of drilling and producing hydrocarbons from an oil well, and more particularly concerns the wiping of a sucker rod as it is withdrawn from a borehole.
2. Description of the Prior Art
In oil well operations, various tubular goods, such as drill pipe, production tubing, and sucker rod must be used downhole in the borehole. In producing the well, it is commonplace to utilize a pump-jack unit which reciprocates a string of sucker rod. The sucker rod extends downhole to a downhole pump. The pump-jack unit reciprocates the rod string which in turn reciprocates the downhole pump so that oil is raised during the upward stroke. Flap valve means at the bottom of the borehole closes on the down stroke to prevent oil from moving back downwardly.
A string of sucker rod is made up of individual joints which are approximately 25 feet in length. The rod joints are connected together by a coupling member. The string of sucker rod may be more than a mile in length. In order to prevent frictional wear of the rod joints against the production tubing, guide units are often emplaced upon the rods at frequent intervals. The guide units are generally comprised of a rubber portion that extends radially outward from the sucker rod to establish sliding contact with the production tubing.
From time to time, it is necessary to pull the entire rod string out of the borehole so that various different repairs or changes can be made to the oil well. This necessitates unscrewing each joint as the string is lifted from the hole. The sucker rod joints are then stacked until the work on the well has been completed and then the rod joints are made back into a string by reversing the above procedure.
The sucker rod often accumulates a coating comprised of paraffin, scale, oxidation products, and other debris. During the lifting operation, it is desired to remove said coating for proper maintenance of the sucker rod and also for the purposes of maintaining a cleaner work environment and preventing the coating ingredients from polluting regions adjacent the oil well.
The wiping of the coating from the sucker rod is often attempted manually with rags, gloves, or other materials. However, this is very dangerous to personnel and often inefficient. Devices have earlier been disclosed for wiping sucker rods, but such devices are unable to accommodate the guides which extend radially from the rod. Other earlier rodwiping devices have been either of complex construction or difficult to install and maintain in proper operating condition.
It is accordingly an object of the present invention to provide a wiping device for the efficient cleaning of sucker rods in an oil well installation.
It is a further object of this invention to provide a device as in the foregoing object which will function effectively on a sucker rod having radially extending guides.
It is a another object of the present invention to provide a device of the aforesaid nature which is easily installable and resistant to malfunction during use.
It is a still further object of this invention to provide a device of the aforesaid nature of simple, durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.