Which direction should a horizontal well that is not intended to be hydraulically fractured be drilled?

Which direction should a horizontal well that is not intended to be hydraulically fractured be drilled?

• A. Along the direction of minimum horizontal stress
• B. Along the direction of maximum horizontal stress
• C. Perpendicular to the horizontal stress
• D. Vertically

Answer: (A)

Drilling a horizontal well along the direction of the smallest horizontal stress puts the bore in the axis of weaker confinement. In that stress field, fractures tend to grow away from the wellbore rather than along its length, making long, along-well fracture paths less likely. If you drilled along the maximum horizontal stress or vertically, the conditions would be more favorable for fracture growth in directions that could extend along the well, which you want to avoid when fracturing isn’t planned. So the best choice is to align the well with the minimum horizontal stress.

Drilling a horizontal well along the direction of the smallest horizontal stress puts the bore in the axis of weaker confinement. In that stress field, fractures tend to grow away from the wellbore rather than along its length, making long, along-well fracture paths less likely. If you drilled along the maximum horizontal stress or vertically, the conditions would be more favorable for fracture growth in directions that could extend along the well, which you want to avoid when fracturing isn’t planned. So the best choice is to align the well with the minimum horizontal stress.