Characteristics of Tight Dolostone Reservoir and Its Main Controlling Factors in the Submember Ma5₅ of Majiagou Formation in the Western Ordos Basin

Figure 5

Lithofacies characteristics of dissolution pore-type dolostone reservoir. (Anh = anhydrite; Bs = breccia structure; Mps = moldic pore by salt dissolution; Gs = geopetal structure; Dpb = dissolved pore between breccias). ((a) Dissolved collapse breccia structure, 3859.85 m, well Y1112; (b) moldic pore by salt dissolution, and geopetal structure, 4089.80 m, well Y1165; (c) moldic pore, 4089.80 m, well Y1165; (d) dissolved pore between breccias, 3952.10 m, well Y1113).

(a)

(b)

(c)

(d)