Horizontal Wells Sandstone Acidizing Analog Design And Software Development,

With the huge advances of the technology and the increasing of the amount of horizontal well, the sandstone acidizing of horizontal well has become an important means to enhance the output of oilfields. Because the pollution characteristics, designing method, treatment parameters and technology of horizontal well is different from vertical well, the model and method of simulation and design of vertical well can not adapt to the situation of horizontal well. To satisfy the requirement of sandstone acidizing technology of horizontal well, this paper accomplished the main contents as followed:(1) Set up the pressure and velocity field model of acid flow for Permeability anisotropic formation matrix acidizing. Through mathematic means of variant separation and transformation, 2D numerical model was changed into 1D numerical model and acquire the single analytic solution of the equation. This model indicated that considering formation anisotropy, except that the equal pressure curve near well bore is circular, others in formation are elliptoid and velocity field distribution is also not circular radial, but present an elliptoid radial flow;(2) Analyzed the characteristics of horizontal well. Based on the law of conservation of mass, this paper applied Carter model, through integral transformation and set up the drilling loss model and polluting equivalent depth and maximal depth of horizontal well. Improved the traditional model of skin factor and adapted it to the situation of horizontal well, and observed the variational regularity and influential factors of skin factor;(3) Set up well bore temperature field model and permeability anisotropic formation temperature field model, and put forward some instructive advices for acidizing job;(4) Set up HC1 preflush acidizing in anisotropic formation model. This model took into account the effect of HC1 preflush on the design of matrix designing and developed the distribution of porosity and permeability after HC1 preflush acidizing;(5) Based on the actual situation of horizontal well, "two-acid, three-mineral" generalized distribution parameter model was introduced and the effect of formation anisotropy was taken into account. It could reflect the actual the reaction process and reaction mechanism. Thus, it could instruct theacidizing design more effective and could improve the ability of the model to anticipate the effect of the acidizing treatment;(6) Presented a method of optimizing treatment parameter of horizontal well matrix acidizing. Considering more factors in the scheme, it is an integral and all-sided method;(7) Programmed horizontal well matrix acidizing software. The interfaces of the software is friendly and convenient in operation. Two successful applications in two horizontal wells of Xinjiang oilfield checked the reasonability and reliability of the software.