04246964 is referenced by 31 patents and cites 5 patents.

A downhole testing apparatus has a modular construction including a pump assembly, a screen assembly, a first packer assembly, an intake port assembly, and a second packer assembly. The pump assembly includes an improved ratchet assembly for opening and closing a relief port of a discharge passage of said pump. The pump assembly is constructed so that said ratchet assembly and the moving components of the pump are covered with a lubricating fluid contained between upper and lower seals.

Title
Down hole pump and testing apparatus
Application Number
6/57093
Publication Number
4246964
Application Date
July 12, 1979
Publication Date
January 27, 1981
Inventor
John T Brandell
Duncan
OK, US
Agent
Lucian Wayne Beavers
James R Duzan
John H Tregoning
Assignee
Halliburton Company
OK, US
IPC
E21B 33/127
E21B 43/00
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