دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

v: to part or open fractures in productive hard limestone formations by using a combination of oil and acid or water and acid under high pressure. See formation fracturing.

to fracture stimulate a formation by injecting the acid over the parting pressure of the rock and using the acid to etch channels in the fracture face.

v: to lower the drill stem rapidly a few feet into the hole and then stop it suddenly with the drawworks brake. A surge of pressure in the mud in the drill stem and annular space results and may help to flush out debris accumulated in or on die pipe. The pressure surge may break down a formation, however, causing lost circulation, or may damage the bit if it is near the bottom.

v: Landing the drill string speedily and then braking. This operation can produce stiring pressure to clean the cutting laying up in the drill pipe. But this pressure may lead to formation fracturing or circulation loss.

n: die fracturing of a formation from excessive borehole pressure.

n: refer to formation fracturing

initiating a fracture in the formation.

n: a method of stimulating production by opening new flow channels in the rock surrounding a production well. Often called a frac job. Under extremely high hydraulic pressure, a fluid (such as distillate, diesel fuel, crude oil, dilute hydrochloric acid. water, or kerosene) is pumped downward through production tubing or drill pipe and forced out below a packer or between two packers. The pressure causes cracks to open in the formation, and die fluid penetrates the formation through the cracks. Sand grains, aluminum pellets, walnut shells. or similar materials (propping agents) are carried in suspension by die fluid into the cracks. When die pressure is released at the surface, the fracturing fluid returns to the well. The cracks partially close on the pellets. leaving channels for oil to flow around them to the well. See explosive fracturing, hydraulic fracturing.

n: a way that increase the production of crude oil by increase layer permeability.

n: see fracture gradient. frac job n: see formation fracturing.

n: The pressure gradient, generally stated in psi/ft [kPa/m], at which a specific formation interval breaks down and accepts fluid. Determining the frac gradient is a key requirement in designing and analyzing a hydraulic fracturing treatment.

n: fracture pressure above which make formation fracture proceeded after formation fracturing.

same as fracture extension pressure.

initial shut-in pressure. Used to isolate the formation fracturing or injection effect from the friction effects.

a cement squeeze technique with a final squeeze pressure below the formation fracturing pressure.

n: a formation-stimulation process first used about a hundred years ago in Pennsylvania. Nitroglycerine is placed in a well and exploded to fracture the rock. Sand and gravel or cement is usually placed above the explosive charge to improve the efficiency of the shot. Nitro shooting has been largely replaced by formation fracturing.

n: a phenomenon in which a rock formation is broken apart along bedding planes or in which natural cracks are widened by the application of hydraulic pressure. It is sometimes called breaking or cracking the formation, earth lifting, or formation fracturing.

n: see hydraulic fracturing.