Study on Mechanism of Improving Sands Carrying Capacity with Double Helix Tubing String in Horizontal Fracturing Wellbore and its Application in Changqing Oilfield

摘要

In this paper, a new type of double helix tubing string is proposed to improve sands carrying capacity in horizontal fracturing well. Meanwhile, two new dynamic models of sands transportation in straight and double helix tubing string are established respectively. The experimental results show that the double helix tubing string can significantly form spiral vortex flow and improve the suspension of sands in horizontal fracturing wellbore. The sands are variably accelerated and transported efficiently in double helix tubing string. Moreover, field experiment also indicates that the double helix tubing string can greatly improve sands carrying capacity and avoid sands deposition in horizontal fracturing well.