Horizontal Well Acidizing Chemical Particles Distribution Process Simulation Studies

With many advantages, horizontal wells attract considerable attention. At the same time, serious formation damage caused by horizontal wells influences productivity of wells. Acidizing plugging removal technique is taken to increase the productivity of horizontal wells. Diverting and placement of acidizing fluid are the main challenging problems. Having properties of convenience, inexpensiveness and wild applicability, chemical diverting Technique can be used to solve these problems.Based on the study of injury model of well Furui-Zhu-Hill, we found the distribution of injury area is elliptic platform close to the hell, and made the mathematical simulation and analysis on Non-uniform skin factor of horizontal wells.This paper established the acid distribution model in horizontal well and the model considered the effects of formation anisotropy and the on-way friction in the borehole. Combining the study results of the damage model with the distribution model, the commingled acidizing process and the radial flow distribution along the wellbore in the horizontal well which has been damaged non-uniformly could be real-simulated at some extent and all of those have the instructive significance for the study of chemical diverting technology in horizontal well.Experiments have shown that the oil-soluble chemical diverting agent A-lhas excellent acid-insoluble ability and oil-soluble ability, the water-soluble chemical diverting agent A-2has excellent acid-insoluble ability and water-soluble ability. The microstructure of the water-soluble chemical diverting agent could be controlled by optimizing the type and the concentration of the surfactant. The experiment simulation of the chemical diverting agent confirmed that the chemical diverting agent can plug the core stably and realize distributary in the core which has permeability differential.Calculation method of pressure drop on filter cake is shown in temporary plugging experiment which is helpful to analysis of experimental data.On the basis of linear skin factor, a reasonable and effective fitting method of diverting experimental data is put forward in this paper, and characteristic parameters a is determined as1.95×102m/kg by using this method.Horizontal wells chemical diverting process model has been established, which can simulate the horizontal wells chemical diverting process authentically and optimize total injection volume and volume concentration of chemical diverting agent. Results show that well bore flow rate non-uniform distribution can be improved by using the chemical diverting agent. The research results put forward in this paper will enrich the existing theory system of horizontal wells chemical diverting technology, and provide some valuable research methods.