Key Drilling Technologies for Shale Gas Well Longye 1HF

Well Longye 1HF is a shale gas wildcat well in the Pengshui block and its formations are characterized by well-developed fractures and pores, large dip angles and poor drillability, so the following technical difficulties tended to occur during its drilling, e.g. leakage, deflection, shale collapse and low ROP (rate of penetration). After the well trajectory, bits and drilling assembly were optimized, the drilling was performed safely and quickly by applying comprehensively near-bit geosteering drilling technique, oil-based drilling fluid and double coagulation-double density cement slurry. It was shown in Well Longye 1HF that no serious leakage occured in the whole well interval and its ROP at highly deviated well interval was 32% higher than those of the shale gas wells in its adjacent area. And furthermore, its reservoir penetrating ratio was up to 100%, drilling cycle was shortened by 25.68% and cementing quality was good. Based on these key drilling technologies adopted in this well, the development cost of shale gas in Pengshui Block could be reduced further.