Note Horizontal Wells Reasonable Sandstone Matrix Acidizing Acid Technology

Horizontal well of sandstone matrix acidizing is different from the vertical matrix acidizing, due to its longer interval, the horizontal section of the damage size is different, its heterogeneity is strong. And because of its high horizontal permeability anisotropy, so the traditional design scheme for vertical Wells acidification is no longer applicable. Because in the process of acidification, reasonable acid injection schemes for the acidification effect is bigger, so designed a in the light of the concrete situation of horizontal well acidizing program is crucial.In this paper, on the basis of predecessors’research, in-depth investigation and study, based on the importance of horizontal well reasonable acid injection, mainly for the important research content:(1) Horizontal well is established matrix acidification acid velocity field and pressure field distribution model, the model for horizontal well acidizing reasonable injection acid solution in the process of design has a vital role. The model shows that, under the influence of anisotropic permeability, formation of isobar of horizontal well is a except for circular wall, the rest are a bunch of concentric ellipses and velocity field of horizontal well acid elliptic radial flow.(2) In this paper, based on the damage characteristics of horizontal well, a new kind of horizontal well is deduced damage skin factor model, the model accuracy is higher than the Frick and Economides models. At the same time in order to estimate the size of the horizontal section damage radius horizontal well drilling is established carter model filtration model and effective invasion depth and the maximum penetration depth model, combined with the traditional method of skin factor calculation at the same time, established a more suitable for calculation of horizontal method of skin factor.(3) Bore temperature field model and permeability anisotropic formation temperature field model are set up in this paper, the model can accurately predict the change in temperature when the injection condition change.(4) A one-acid, two mineral model for anisotropic reservoir matrix acidizing of horizontal well is set up. The situation that acidizing model can be used only for isotropic is changed by using this model. The predicting ability of treatment effect is improved.(5) Is deduced for sandstone matrix acidizing of horizontal permeability anisotropy is bigger, in the process of damage heterogeneity of acid stimulation times than the model, the model for predicting acidification effect is of great importance.(6) In this paper, according to the characteristics of the horizontal well damage, combined with previously established acidification model, by changing the conditions in the process of acid injection, to select a reasonable injection acid solution.