Hydraulic fracturing of low permeability reservoirs with multiple fractures is an effective stimulation treatment in the serial techniques of horizontal well production. The comprehensive mathematical model of predicting the production performance of a hydraulically fractured horizontal well with multiple fractures, combined the reservoir model and type of reservoir derive with the hydraulic fracture model is first established in this paper. The numerical models and the corresponding solution are first derived. Both fracture performance and reservoir performance in the transient producing period or pseudosteady producing period are taken into account. These models are applied to simulate the pressure performance of reservoir and multiple fractures in the horizontal well, to forecast the well production in the transient producing period and pseudosteady producing period. This paper investigates optimization of fracture numbers in the horizontal well, added the fracturing economic evaluation model to the comprehensive mathematical model. A case study is shown which demonstrates the method of forecasting production and optimizing fractures numbers. These models and the methodology can be employed in fracturing design of a horizontal well and evaluation of fracturing effectiveness.
Hydraulic fracturing of horizontal wells, which enhances the oil reserves in the low permeability reservoir and keeps the oil wells high productivity is becoming an effective stimulation treatment in the serial techniques of horizontal well exploitation. Forecasting the production performance of a hydraulically fractured horizontal well plays an important role in the optimization design of hydraulically fracturing the horizontal well, furthermore it is the main basis of evaluating the effectiveness of post-fractured wells. Segment fracturing in the horizontal wells commonly induces multiple fractures which are oriented near the wellbore. Predicting the production performance of a fractured horizontal well with single fracture or several fractures can be used to determine the optimum fracture numbers and to improve the design of hydraulic fracturing treatment.
This paper first presents the comprehensive mathematical model of predicting the production performance of a hydraulically fractured horizontal well with multiple fractures. The reservoir model, type of reservoir drive and hydraulic fracture model are included in the comprehensive model. Both pressure behaviors in the fractures or in the reservoir and well production in the transient producing period and pseudosteady producing period can be simulated. The fracturing economic evaluation model is introduced to investigate the optimization of numbers of fractures in fractured horizontal wells. A case study is presented which demonstrates the method of forecasting production and optimizing fracture numbers. These models and methodology can be employed in fracturing design of a horizontal well and evaluation of fracturing effectiveness.
The object of this study is shown in figure 1 in which a fractured horizontal well with multiple fractures is located in the rectangular reservoir. The following assumptions are involved in the derivations of the mathematical model.
The fractures are perpendicular to the wellhole and vertically penetrate the partial reservoir thickness.
The horizontal well fully penetrates the reservoir or unfully penetrates the reservoir.
