Increased focus on extending the reach of horizontal shale completions has led to new challenges that must be overcome by technological advancements in the drilling and completion process. Longer laterals are contributing to liner running challenges which can cause significant NPT and ultimately decrease the economic viability of wells through increased costs or reductions in the extent of reservoir accessed. This paper presents a field case history demonstrating the role of centralizers in successfully overcoming a liner running issue, and highlights an opportunity for enabling longer-reach wells.
Enerplus had encountered liner running issues with one of its long-reach Three Forks shale wells, resulting in a much longer-than-anticipated run time. One measure taken to address this challenge was to revisit centralization practices for cemented horizontal liners. Two specific aspects of Enerplus' liner configuration were reconsidered: the centralizer selected and the placement of the centralizers along the length of the liner. Whereas centralizer placement is typically based on pipe-to-borehole standoff considerations for zonal isolation after cementing, an augmented engineering basis that also considered mitigation of buckling-induced side loads during running was adopted. In a first field trial using this solution, torque-and-drag predictions were used together with this advanced centralizer placement basis to determine a centralizer distribution.
Although only a modest increase in centralizer quantity was used compared to the prior offset well, the field trial was very successful, and post-run analysis indicates significantly less drag and lockup potential relative to the prior well as TD was reached. Significant savings in liner running time (on the order of 50%) were achieved relative to the prior completion where issues were encountered.
Data gathered for comparison of these two very similar wells in the same field with different centralization solutions provides an excellent basis for assessing Enerplus' future centralizer configurations, and for assessing reach limitations should there be a desire to extend future wells of this type beyond the 4,500 m horizontal length achieved in this trial.