Hydrostatic bailers and wireline jars (hydraulic suction bailer)
The Cavins Hydrostatic Bailer has been used in all types of clean-out work in producing wells and in drilling and workover operations. Its principle use of hydraulic suction provides several distinct advantages that cannot be obtained with any other type of wireline cleanout tool.
Using hydraulic suction creates a more efficient method of recovery, whether the material to be recovered is loose or packed, hard or soft, metallic or non-metallic. Tremendous velocity is attained by the fluid that surges into the Bailer when it is activated, and anything caught in its current is swept into the retaining section of the tool. Furthermore, the suction creates a great disturbance at the bottom of the well, and this has the benefit of breaking up hard sand bridges, packed shale, etc., and loosens scale and other foreign matter on the walls of the screen or perforated section.
Hydraulic suction also tends to aerate the fluid on the bottom, so that a certain amount of compression is obtained as the fluid column “falls” when the Bailer is activated. With this compression, a re-surge of fluid occurs immediately and an “ebb and flow” effect is created. This effect further tends to break up and loosen materials, thus assuring a more complete recovery.
In cased wells, hydraulic suctions adds another benefit by loosening material outside the pipe, washing it through the screen or perforations to the inside where it can be recovered by subsequent runs of the Bailer. This is of great importance, since very little is gained by cleaning inside the pipe if the perforation tunnels and sand outside the casing is compacted.
Several types of bottom attachments permit the Hydrostatic Bailer to be used for straight bailing, breaking up and removing bridges, and for many fishing operations. Its efficiency in these various services will save thousands of dollars in well-maintenance work.
Rod-Type Sand Pump
Cavins Sand Pumps are designed for clean-out work where it is not desired to flush the producing formation with hydrostatic fluid surges, or where extremely low fluid levels prevent efficient use of the Cavins Hydrostatic Bailer. In such wells, the sand pump effectively removes soft sand, shale and other matter. The Sand Pump is designed to operate in either light or heavy fluids with equal efficiency.
Cavins Sand Pumps are available for use inside all standard sizes of casing, and the tool ranges in size, from 1.25” to 4.5” OD.