On November 21st, the first ultra deep shale gas new layer test well in China, Daye 1H1-2 well, was successfully drilled with a completion period of only 78.94 days, breaking the record for drilling cycle in the well area.
The exploration horizon is an important replacement for shale gas development in the Sichuan Basin, with favorable factors such as excellent sedimentary and preservation conditions, good reservoir quality, excellent engineering conditions, and relatively low formation temperature. However, at the same time, the burial depth of the strata is large, and there is a risk of long section leakage in the upper strata, high sulfur content in the FXG group, and the possibility of encountering abnormal high pressure and goaf during drilling, which poses a greater risk of leakage and overflow; The natural inclination ability of the formation is strong, and the displacement at the bottom of the vertical well section is prone to exceed the standard; ZLJ, XJH and other formations have strong rock abrasiveness and poor drillability, with low drilling speed and long cycle for large-sized well sections; The formation pressure is complex, the drilling is difficult, and the well control risk is high, requiring strict requirements for drilling fluid, casing string, and entry tools.
This significant breakthrough in the exploration of new shale gas formations in ultra deep layers not only injects strong impetus into the development of China’s shale gas industry, but also provides valuable experience for domestic shale gas exploration and development.
Post time: Dec-07-2024