Abstract:

Nowadays the fractured horizontal well technology has become an important method for developing the low permeability gas reservoirs around the world, so correctly predicting the fractured horizontal well productivity is essential to the design of the horizontal well development program, and the sensitivity analysis of formation and fracture parameters. A percolation model of the fractured well in low permeability reservoirs was presented in this paper, which includes the coupling of formation percolation and horizontal flow in the horizontal wellbore by using the complex potential theory, potential superposition principle, fluid mechanics theory, as well as the real gas state equations. According to the characteristics of the model, the ioluasabe. Furthermore, some practical examples of the low permeability gas reservoirs in Changqing oilfield were calculated for comparison. The calculation results showed that: (1) The pressure drops in the horizontal wellbore had some effect upon the production performance of the fractured horizontal well; (2) The pressure distribution along the horizontal well was not well-proportioned, (3) not equal for each fracture production. This paper also analyzed those parameters which aff tlbesros and fractured horizontal well's production, such as wellbore radius, horizontal section's length, fracture number and pipe-wall roughness, finally some useful conclusions were obtained.

Key words: low permeability gas reservoirs, fractured horizontal well, coupling model, productivity