Determination of Formation Time of Calcareous Cements in Marine Sandstone and Their Influence on Hydrocarbon Accumulation: A Case Study of the Carboniferous Donghe Sandstone in the Hadexun Oilfield, Tarim Basin

Table 2

Percentages of cements of different phases in calcareous interlayers within the Donghe sandstone, Hadexun Oilfield.

Well no.	Depth/m	Lithology	Percentage of cements of different phases/%
			Phase I	Phase II	Phase III
Well HD4	5070.07	Sandstone		81.8	18.2
Well HD4	5070.62	Sandstone		73.3	26.7
Well HD4	5098.52	Sandstone	0.8	50.1	49.1
Well HD17	5529.01	Sandstone		55.3	44.7
Well HD17	5529.47	Sandstone		49.9	50.1
Well HD17	5230.13	Sandstone		60.1	39.9