Zm. Chen et Mj. Economides, Effect of near-wellbore fracture geometry on fracture execution and post-treatment well production of deviated and horizontal wells, SPE PROD FA, 14(3), 1999, pp. 177-186
The near-wellbore fracture geometry is important to hydraulic fracture exec
ution and the subsequent post-treatment well performance. A fracture from a
n arbitrarily oriented well "cuts" the wellbore at an angle and this limits
the communication between the wellbore and reservoir. The stress concentra
tion around the wellbore further complicates the near-wellbore fracture geo
metry. The fracture width at the wellbore can be much smaller than the maxi
mum width, or it may even close when the fracturing pressure decreases belo
w some critical value. The limited communication path may cause a "screenou
t" during fracture execution or large reduction in the subsequent productio
n because of choked fracture effects. This paper first discusses fracturing
conditions for an optimal communication path between the wellbore and the
reservoir. The near-wellbore fracture geometry is then determined. The effe
cts of this fracture geometry on fracture execution and production are disc
ussed. Critical fracturing pressures are also calculated for different well
bore orientations and in-situ principal stress magnitudes. Guidelines are p
rovided to enhance the success of fracturing treatments.