Using a Catenary Trajectory to Reduce Wellbore Friction in Horizontal Extended Reach Drilling

TL;DR

This paper explores using a catenary-shaped drill string trajectory to minimize wellbore friction and torque in extended reach drilling, comparing it to traditional arc designs through a case study and an accessible Excel tool.

Contribution

It introduces a practical method for designing catenary well trajectories to reduce friction, filling a gap in detailed analysis for extended reach drilling.

Findings

Catenary trajectory design reduces wellbore friction compared to traditional methods.

An easy-to-use Excel tool for designing catenary well paths is provided.

Case study demonstrates the effectiveness of the catenary approach.

Abstract

Wellbore friction is one of the biggest concerns when drilling due to its relation to the total cost. The catenary concept was introduced to reduce wellbore friction, but it requires detailed analyses. This project would fill this gap. A catenary shape is simply the natural shape of a rope, chain, or drill string. The drill string will then hang freely inside the wellbore. Perfectly, there should be no contact between the hole and the string, and thus no friction. Torque and drag should be minimized this way. A case study is introduced to examine the outcome between Catenary Trajectory Design and traditional 2D Arc design. The calculation procedure of Catenary Trajectory and 2D Arc Design can be found in an MS Excel spreadsheet which is easy to use and reliable for designing catenary well trajectories for extended-reach wells.