Transformation mechanism of muddy carbonate rock by the coupling of bioturbation and diagenesis: A case study of the Cretaceous of the Mesopotamia Basin in the Middle East

YE Yu,LI Fengfeng,SONG Xinmin,GUO Rui

Fig. 9. Core characteristics affected by the coupling of bioturbation with dissolution in Mishrif Formation in Well M316 in H Oilfield. (a) Type I: H oilfield, Well M316, 2918.0-2919.0 m. The whole section is dissolution, and the outlines of the burrows are difficult to identify. (b) Type II: H oilfield, Well M316, 2936.0-2937.0 m. The whole section is weakly dissolution, and the outlines of the burrows are clear in mazy shape. (c) Type III: H oilfield, Well M316, 2937.0-2939.0 m. The upper section is dissolution, and the outlines of the burrows are difficult to identify. The lower section is weakly dissolution, and the outlines of the burrows are clear in mazy shape. The interface between the dissolution zone and the weakly dissolution change gradually. (d) Type Ⅳ: H oilfield, Well M316, 2880.0-2880.5 m. The upper section is weakly dissolution, and the outlines of the burrows are clear in mazy shape. The lower section is not dissolution, and the burrows are in mottled shape and patched shape. (e) Type V: H oilfield, Well M316, 2921.0-2922.0 m. The upper section is dissolution, but the lower section is not dissolution. The burrows are in vein shape or mazy shape. The interface between the dissolution zone and the non-dissolution change abruptly. (f) Type VI: H oilfield, Well M316, 2973.0-2974.0 m. The upper section is dissolution, but the lower section is not disturbed by organisms. The core is gray and dense. (g) Type Ⅶ: H oilfield, Well M316, 2914.0-2914.4 m. The upper section is dissolution, but the lower section is not dissolution. The burrows are in mottled shape. The middle section is the transition zone, and the burrows are in vein shape or mazy shape.