Drilling long HTHP multi-lateral wells
The AST principle provides a stabilized load on the bit in lateral and extended reach wells to prevent erratic reactive torque that would otherwise reduce drilling efficiency.
The Smørbukk Sør province in the Statoil-operated Åsgard field represents a significant drilling challenge with long multilaterals penetrating abrasive sands at HTHP conditions. AST technology was mobilized early in the project.
In support of a step-by-step approach, the operator conducted several direct comparisons to verify the added value of the new technology. It was found that an AST would reduce the weight-on-bit requirement and consequently reduce stick-slip from pipe friction while at the same time increase penetration in the range of 15-100%.
Based on the improved progress, approximately two days or about USD 1.6 million was saved per lateral.
ROP bars showing the effect of the AST. WOB is also plotted to illustrate the highly valued reduction in string compression.