Optimal and fast drilling technologies applied in the toothbrush-like oil reservoirs in Yangwuzhai structural zone

Yangwuzhai structural zone is one of the hydrocarbon enrichment zones in Raoyang sag, and its resource potential is huge. Its oil layers are distributed in the shape of toothbrush, so in order to increase the drilling thickness of oil layers and the reserve control degree of oil reservoirs, the drilling mode is transformed into the high-angle directional well from the vertical well in the early stage. In this paper, optimal and fast drilling technologies were studied, including track section selection, ROP (rate of penetration) improvement tool selection and drilling fluid property optimization, to deal with the problems in the drilling process of directional well, e.g. serious backing pressure, hard control of tool face, low ROP, frequent pipe sticking in Tertiary and vulnerable low-permeability reservoir. When the optimal and fast drilling technologies are applied to the field, directional and continuous drilling without backing pressure and sticking is realized. And compared with the same depth in its neighboring well, its average ROP is 50.5% higher and drilling period is 9 d shorter. The research results can be popularized and applied in the similar oil reservoirs.