Well Engineering Innovation

Riserless casing drilling Value

Mitigate shallow hazards

Casing Drilling’s smearing effect & narrow annulus

  • higher circulating friction increases bottom hole pressure

  • strengthens wellbore with plastering drilling cuttings into formation

  • allows casing depths to be based upon prevailing pore pressure & fracture gradients

 

Conventional vs Casing Drilling Geometries

Deepen structural casing

  • rapid growth of shallow fracture gradient allows deeper casing shoe for higher formation strength (Allows higher mud densities to mitigate hazards)

  • less casing strings in riserless section allow larger casing strings deeper in well design

  • mitigate loss-kick cycle

  • reduces use of contingency casing strings

 

Prevailing Pores Pressure & Fracture Gradient determines casing design to optimize casing design

Larger drilling operating windows in lower well sections

  • decreases circulating friction (minimizes fluid loss - kick cycle)

  • creates opportunity for contingency casing strings

 

Larger hole section across objectives

  • Larger completion

  • Increase production rates, improved economics

 

Reduction in total well time

  • less hole sections / casing strings

  • single trip to drill hole section & run casing

Allows setting high pressure conductor deeper

Allows larger tubing string, less back pressure, higher production

Value in the riserless sections sets up increased value in lower sections