TDDirect CD Casing-While-Drilling Service

Specialty Drilling Applications

Casing-drilling and liner-drilling technology

Eliminate dedicated casing runs by casing and isolating the formation while drilling

Casing- and liner-while-drilling technology delivers a high-quality wellbore because each foot of the borehole is drilled and cased off simultaneously, eliminating the need for separate casing or liner runs. When TD is reached, the borehole is ready for cementing. Compared with the performance of conventional drilling systems, Schlumberger's casing- and liner-while-drilling technology has recorded equal or better on-bottom ROP and has reduced the time spent on drilling and casing operations by more than 30%.

Greater borehole stability and well control

Using casing as a drillstring smears cuttings into the borehole wall, resulting in an action termed the plastering effect. This action strengthens the wellbore while it seals pores in the formation to reduce fluid loss.

Drilling with conventional drillpipe (left) allows a larger annulus, while drilling with casing (right) minimizes annulus size; rotating casing smears cuttings into the borehole wall, sealing pores in the formation to reduce fluid losses and producing a stronger borehole for improved cementing.

Maximize reservoir contact and produce while drilling

Directionally drilling with coiled tubing (CT) technology maximizes production in short-radius applications. Specifically designed to access additional reserves in thru-tubing reentry drilling applications, Schlumberger's CT directional drilling technology maximizes reservoir contact without the cost of removing existing completions or production tubing—all while producing the reservoir and minimizing formation damage.