Abstract:

The target exploitation interval of CCL oilfield belongs to Fuyu reservoir in the 4th member of Quantou formation of lower Cretaceous, which has the characteristics of high viscosity, poor fluidity, low pressure and low temperature. Some difficulties exists in the the process of fracturing, for example, cold damage due to the incompatibility between the fluid and reservoir, unmanageable crack height caused by developed thin oil layer and and weak blocking ability of the interlayer, and low flowback rate because of the shallow buried depth, low formation pressure and the serious out put formation sand after fracturing. Combined with the optimization of the indoor fracturing materials, low concentration guanidine colloid system is used as fracturing fluid and 16~30 mesh quartz sand as proppant. The technology of front hot water+temporary plugging steering and variable displacement+synchronous interference+integral modification is proposed. The software FracproPT is used to simulate the half length of artificial fracture and the conductivity of fracture, and then to determine the fracturing scale and optimize the design parameters. After field test, the effect is obvious. The oil increment of a single well is twice as much as that of conventional fracturing, which can effectively slow down the decline of oil production of a single well. This modification technology provides technical guarantee for CCL oilfield to increase production of single well and achieve the goal of stable and increasing production.

Key words: CCL Oilfield, difficulty in fracturing, fracturing optimization, whole reconstruction, fracturing technology