Pressure-controlled accumulator charging valve system for...

Pressure-medium driven percussion device

Pressure-medium operated percussion or impact apparatus

Pressure-operated oil and gas well swabbing device

Pressure-up/blowdown combustion - a channelled reservoir...

Pressurized fluid flow system for a reverse circulation hammer

Pressurized medium actuated gripping device

Pressurized system for protecting signal transfer capability...

Prestressed elastic arched mine roof support

Prestressing of mine props

Preventing fines migration by producing from horizontal holes

Preventing fluid migration around a well casing

Preventing freeze-up of ice holes

Preventing plugging by insoluble salts in a...

Prevention of cone seal failures in rock bits

Prevention of gas coning

Prevention of sand plugging of oil well pumps

Prevention of scale in petroleum production by alkaline floods

Prevention of water and condensate blocks in wells

Prevention or reduction of particle migration in hydrocarbon...