Baker International Inc.

Baker Oil Tools, Inc.

Lyndon R Stone

Rudy B Callihan

James D Hall

This invention provides a method and apparatus for effecting two stage cementing of well conduits by supplying cement through a tubular member. The apparatus involved provides a tubular conduit extension attachable to the bottom end of a well conduit and defines a cementing passage through its bottom end. Cementing ports are provided in the extension at a distance above its bottom end. A pair of concentrically adjacent valve units are communicable with the extension with the inner valve unit positioned in a closed position relative to the cement ports. The inner valve unit defines a seal bore which receives a mandrel which is secured to the tubular member. The mandrel incorporates two pilot sleeve valves which are positioned in closing relationship to radial passages in the hollow mandrel and each of which defines an upwardly facing surface for reception of sealing balls or plugs. The first stage of the cementing is accomplished by flow of cement from the tubular member through the mandrel and the extension and out the bottom end thereof. A sealing ball or plug is then dropped through the tubular member into engagement with the lower pilot sleeve valve. Increased pressure urges the lower pilot sleeve valve to open the radial cementing passages in the mandrel and then shifts the inner valve unit to open the cementing ports in the tubular extension. The second stage of cementing can then be accomplished by cement introduced through the tubular member and passing outwardly through the mandrel passages and the radial cement ports. A plug is pumped down the tubular member into engagement with the upper pilot sleeve valve. Increased fluid pressure shifts the upper pilot sleeve valve to expose a passage in the mandrel and provide flow to a chamber surrounding a surface on the second outer valve unit. Increased fluid pressure in the bore of the tubular member will then produce a shifting of the second outer valve unit to seal the cement ports.

Method and apparatus for well cementing through a tubular member

An apparatus for controlling the number of turns made and the torque applied during the operation of making a threaded joint includes a high resolution turns counter. The turns counter senses the rotation of a member of the joint and generates a pulsed signal, each pulse representing a predetermined increment of rotation. The turns counter includes an idler wheel driven by one member of the joint and in turn driving an encoder which generates a relatively large number of pulses per revolution of the idler wheel. A presettable divide-by-N circuit is utilized to divide the encoder pulses to generate a pulse train to a monitoring and control apparatus for indicating whether a good or a bad joint has been made. The divide-by-N counter can be preset to generate a predetermined number of pulses per revolution of the joint member or pulses representing a predetermined percentage of a total number of turns to be made.

Apparatus for counting turns when making threaded joints including an

An apparatus for effecting two stage cementing of well conduits by supplying cement through a smaller diameter tubular member. The apparatus involved provides a tubular assembly attachable to the bottom end of a well conduit. The tubular assembly defines an axial cementing passage through its bottom end. Cementing ports are provided in the tubular assembly above its bottom end to implement the second stage cementing operation. A tubular member is sealingly secured in the upper end of the tubular assembly and valve units are provided between the end of the tubular member and the cementing ports. The lower annular valve unit is selectively releasably positioned in a closed position relative to the radial cement ports. At the conclusion of the first stage of cementing, a first sealing plug is dropped through the tubular member into sealing engagement with the bore of the lower annular valve unit and fluid is applied through the tubular member to shift the lower annular valve unit to an open position. After the second stage, a second sealing plug is dropped through the tubular member to seal the bore of the upper annular valve unit and fluid pressure applied through the tubular member will effect the displacement of the upper annular valve unit to a position sealing the radial cementing ports.

Apparatus for well cementing through a tubular member

An apparatus is provided for controlling the speed of rotation of a joint member during the operation of making a threaded joint. At lower speeds of rotation, a counter means receives clock pulses generated at a predetermined frequency and counts down from a stored value representing the elapsed time for a maximum rate at which turn signal pulses generated during predetermined increments of rotation of the joint member should be generated. If the elapsed time between the turn signal pulses is less than or equal to the stored time, a signal is generated to slow down the joint making operation. At higher speeds of rotation, a counter means receives the turn signal pulses and counts down from a stored value representing the maximum number of turn signal pulses which should be generated in a predetermined time interval. If the turn signal pulse total exceeds the maximum number during the predetermined time interval, the slow down signal is generated.

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San Antonio, TX, United States of America

Lyndon R Stone