Title: Well cementing/plug drilling apparatus and improved cementing and drilling process

Abstract: A cementing/plug drilling apparatus consists of a flat plate slightly less in maximum diameter than the pipe in which it will pass having at least one protrusion or tooth on both faces, the tooth being strong enough and sharp enough to engage, dent and penetrate a cement surface and a pump down wipe plug and, the plate having an opening on each face in fluid communication with each other through a fluid passage. An improved process of cementing and drilling through a pump down wipe plug comprises placing a plate having teeth on both faces between a pump down wipe plug and the surface that the bottom of the plug contacts during the cementing process, so that when the drill bit contacts the plug the teeth on the top of the plate engage and hold the plug and the teeth on the bottom of the plate engage and hold the surface on which they are in contact, thereby retarding the tendency of the plug to slide over the surface below it and enhancing the drilling action of the drill bit.

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Inventors: Davis, Carl A. (Houston, TX, US)

Application Number: 941161
Filing Date: 1978-09-11
Publication_date: 1980-02-26
Assignee:
Primary Class(es): 166/291 166/153, 166/193, 411/533
Other Classes:
US Patent Ref:

628941	Jul, 1899	Janney	85/50.
880597	Mar, 1908	Syze	166/242.
1362623	Dec, 1920	Hochberger	85/50.
1777614	Oct, 1930	Hauger	85/51.
2079140	May, 1937	Yarbrough	166/237.
2162261	Jun, 1939	Layne	166/291.
2165433	Jul, 1939	Wickersham	166/153.
2309791	Feb, 1943	Sanders	166/285.
2922669	Jan, 1960	Hansen	85/50.
3581817	Jun, 1971	Kammere, Jr.	166/285.
3913686	Oct, 1975	Manso, Jr.	166/242.

Other Refs: 359715213669144206

Sep, 1922	DE2
Feb, 1961	DE
Oct, 1938	NL

Primary Examiner: Novosad, Stephen J.
Assistant Examiner: Suchfield, George A.
Attorney: