关键词: 深部煤储层；压裂曲线；低渗透率；目标次分层；郑庄区块 

Abstract: This paper uses Nolte-Smith net double logarithmic pressure-time curve, combined with in-situ operating curve changes, to establish 8 types of hydraulic-fracturing sanding curve, which are employed to study the fracturing curves in 230 beds in 120 wells in Zhengzhuang well field and the deep coal reservoir fracturing effect, aiming at offering references for fracturing design, adjusting operating parameters. Type NS-III-3 (interlayered end-desanding and halt-sanding-return-discharging process) and NS-IV-3 (object layer sub-layer pressure discharging process) are the premium fracturing curves of deep low-permeable coal reservoir in Zhengzhuang well field. Fracturing net pressure works on the original coal fissures, with fissures opened to connect coal sub-layers; then franc sand and fracturing liquid move to the interfaces of coal reservoir sub-layers along its original fissures. Medium-low permeable “sweet spot” areas exist in the deep coal reservoir, which may be considered as a supplement. 

Key words: deep coal reservoir, fracturing curve, low permeability, subject sub-layer, Zhengzhuang block