Analysis For Productivity Of Hydraulic Fractured Horizontal Well

In according to much experience of the oil field development, it has indicated that thehorizontal well technique is an optimal exploitation way to some special reservoirs, such as thinreservoirs, low permeability reservoirs, heavy reservoirs and so on. With the horizontal well, itincreases the contact area between the wellbore and oil layers, improves the output and the finalrecovery ratio, but sometimes, in an ultra-low permeable reservoir, single horizontal well outputis lower. In order to increase the exploitation economy efficiency, we stimulated a horizontalwell with hydraulic fracturing, make multiple vertical fractures to expand the drainage area ofthe well, and then improve the productivity.In recent years, the formulae of the hydraulically fractured horizontal wells areinvestigated continuously. Most of formulae are provided by using conformal transformation,superposition principle, and complex potential theory.In order to analyze the relationship between the productivity and pressure for the multiplefractured horizontal wells, this dissertation studies the common naked hole horizontal well,analyzes the its factor impact. Basic on the theories of porous flow, applied for the advancedmathematics theories, such as point source function, Green function, Laplace transformation,Fourier transformation, derived the productivity for the well with infinite vertical fractures inthe condition of the unsteady or pseudo-steady state. With the equivalent radius from thefracture length, it deduces the productivity formula and then analyzes the mechanism of porousflow.Different reservoir and fracture have the various flow principles. For the rectangularreservoir, circular bounded reservoir, the correspondent fracture system and horizontal wells,this dissertation explains and deduces the relevant mathematical modeling, analyzes theadvantages and disadvantages, and gains the geometric parameters and the physical propertyparameters of the formation and fractures. By analyzing key factors of rate of the fracturedhorizontal well, including the fracture numbers, distance, horizontal well length and the ratedistribution along fracture which can equip theory foundation with the optimal design, and it isvalid to efficiently direct the field practice.