Abstract: D1Ⅰ sub-member of Haiwaihe oilfield is sand-gravel heavy oil reservoir that formed under regional uplifting background,it is only reported reserve 6.72 million ton in the principal portion that is XH27 block.Through the research of hydrocarbon accumulation factors that include source rock,hydrocarbon migration channel and favorable conditions for oil and gas forming,reserving and covering.And combined with the reexamination of "three kinds of the old existed data",it proved this area has expanding potential.It is using fine interpretation to reworkable structure formation,secondary log interpretation to divide to identification standards for corresponding reservoirs which increased reserves to 2.1 million ton,and rolling and expanding well realized the predicted effect.