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Objectives/Scope: The length of horizontal section has a direct effect on heavy oil development efficiency. In order to calculate the extension limit of ultra-shallow horizontal wells in Venezuela heavy oil reservoir and provide theoretical reference for reasonable horizontal well design, this paper analyzed extension ability of ultra-shallow large displacement horizontal wells and give the reasonable extension length of horizontal section and reasonable drilling platform arrangement. Methods, Procedures, Process: Analyze the main factors that impact the horizontal section length in heavy oil formation. Calculate the friction coefficient through measured data. By optimizing the well trajectory and BHA, establishing models for predicting torque and drag of horizontal wells and analyzing hydraulic parameter effect on extension ability of long horizontal section wells, the author calculate the mechanical extension limit and hydraulic extension limit of horizontal wells. Results, Observations, Conclusions: Comparing the two extension limit, we find that ultimate extension length of horizontal section is mainly constrained by torque and drag. thereby the safety maximum extension length of horizontal section in heavy oil is predicted accurately. On this basis, we put forward a new interleaving well spacing design. Novel/Additive Information: The result of this paper can provide theoretical reference for reasonable horizontal well trajectory design and horizontal length design. The novel interleaving well spacing design can help reduce the dead oil area significantly and increase the controllable reservoirs, which is of great importance to oil operator. |
