Abstract
Chang 8 oil deposit, developed in Hohe oil field at the southern Yi-Shan Slop of Ordos Basin, is regarded as a kind of typical sand reservoir formation with super-low porosity, poor permeability, strong anisotropy as well as locally natural faults and fractures. Matrix reservoir has a poor permeability, but fracture reservoir has a reverse manner. In the past years, fewer researchers paid their attentions to study matrix-fracture type oil reservoir, therefore today it is still difficult to identify whether network hydraulic fracturing can be effectively exploited in low permeable matrix-fracture type reservoir. In this paper, the author tries to analyze the feasibility of network hydraulic fracturing application in Chang 8 oil deposit from following aspects: mineral component, rock brittleness index, development status of natural fractures, ground stress and net press during hydraulic fracturing. The statistical results indicate that the geological condition of research object is confirmed to meet the standard of hydraulic fracturing with medium brittleness index, high angle, developed natural fracture and horizontal layers as well as the difference of two principal horizontal stresses 5.4 MPa. The paper performed field investigation in HH6P2 well by the methods of segmental perforation, interference between multiple clusters and boosting net pressure. Then its daily output was up to 2.58 t. Finally, the paper concluded that it is an important treatment to effectively develop this type of oil reservoirs by “Fracture network” fracturing technique in horizontal wells.
