Acidification Simulation And Software Compilation Of Horizontal Wells In Sandstone Reservoirs

Because of constantly research on the acidizing mechanism of the vertical well, we have succeeded in field practice and formed mature theory and practice system of acidizing. For the horizontal well, it is different from vertical well because of its pollution characteristics, designing methods, treatment parameters and technology. On the basis of former researchers, to satisfy the requirement of sandstone acidizing technology of horizontal well, calculation of design method for horizontal well matrix acidizing is researched. The major content is as following:1. The velocity and pressure model of acid flow for permeability anisotropic formation matrix acidizing of horizontal well is developed. It simulates distribution velocity of flow of liquid flooding in immediate vicinity of wellbore, is the base of simulation of formation temperature field distribution model, HCL preflush design, acid and mineral model.2. Analyze the features of horizontal well, and set up horizontal well damage model.On the basis of tradditional skin factor model, horizontal well skin factor caculated model is set up.3. With consideration of friction heating of the horizontal well, well bore temperature field model is set up in different fluid pumping system. With consideration of heat of recation between acid and mineral, permeability anisotropic formation temperature field model is set up. Temperature affect characterization of acid and reaction rate of acid-rock widely.4. In matrix acidizing designing of horizontal well, the impact of HCL preflush must be taken into account, and set up HCL preflush and Carbonate distribution model.5. On the basis of traditional "one-acid, two-mineral"model,the anisotropy formation "two-acid, three-mineral" generalized distrbution parameter model is set up,which cansider impact of depositing Si(OH)4 and H2SiF6 intermediary on acidizing effect, and the anisotropy formation was taken into account. It improves the ability of the model to anticipate the effect of the acidizing treatment.6. The job technlogy and practice recommend for horizontal well acidizing is brought forward, the method of optimizing job parameter and effect evaluation of acidizing is presented.7. Based on the models above, the software is developed for the design of horizontal well acidizing. The applicability and reliability of the sofeware is checked by calculation with the data of a horizontal well in oilfield.