Hydraulic fracturing new processes and new technologies

1, End  frac sand  fracturing technology (TSO)
With the development of oil and gas field exploration techniques and a variety of cross-technology integrated use of fracturing technology applications are no longer confined to low-permeability formations, high permeability formations have begun to use this technology to improve development results. When fracturing technology used in high permeability formations, hoping to form a short, wide cracks and crack control as much as possible within the reservoir. In order to meet the requirements of this particular foreign mid-80s in the 20th century developed the ends off the  frac sand  fracturing technology, and quickly applied to the scene, the current domestic also carried out research in this area, and has made great progress .

(1) End  frac sand  fracturing the basic principles
End  frac sand  fracturing is in the process of hydraulic fracturing, conscious that the fracture  Proppant   frac sand  off the ends to form a frac sand plug to prevent further fractures extending forward; continue after injection of a high concentration of the cracks in the mortar net pressure increases, forcing the expansion wider cracks, fractures filled with  frac sand  concentration becomes large, so create a wide and a higher fracture conductivity. End frac sand  fracturing is the key to success off the  frac sand  around the crack, the crack on the bottom of the front and not from any part of the  frac sand  can not fully achieve the intended purpose.

End frac sand fracturing in two different stages. The first stage is built off the frac sandseam to the end, which is actually a conventional  Hydraulic fracturing  process, the current two-dimensional or three-dimensional model can be applied. The second stage is the expansion cracks widened and proppant filling stage, this stage of the design is based on the material balance based on the first stage of the final moments of the relevant parameters as input parameters to complete.

(2) off the end of the technical characteristics of frac sand fracturing
In the End frac sand fracturing technology, the fracturing fluid viscosity to meet two requirements: First, ensure that the liquid can be suspended frac sand, two frac sand off is beneficial.

If the fracturing fluid viscosity is too low, the liquid can not guarantee suspending frac sand, there will be no cracks in the upper frac sand zone, reach the surrounding frac sand off purposes, in the construction process can easily lead to the wellbore grit. If the fracturing fluid viscosity is too high, fluid loss will slow, difficult to timely removal of frac sand. So ends off the frac sand fracturing technique of fracturing fluid viscosity requirements than conventional fracturing fluid to be stricter.

And compared to conventional fracturing, End frac sand fracturing technology infusion displacement is smaller, which is to slow the rate of crack extension, control joints and ease off the high frac sand. Preflush amount less than conventional fracturing, the purpose is to make the mortar in the leading edge of the pump stops before it reaches the crack periphery. The End frac sand frac sand ratio is usually higher than conventional fracturing to improve the efficiency of the support of cracks.

(3) End frac sand fracturing scope
End frac sand fracturing technology is characterized by cracks caused by the surrounding frac sand off pressureout short wide slit, so only under certain conditions. Mainly used in shallow or deep stratum (stratum can pressureout), high penetration or soft ground and must be strictly limited fracture height strata.