Influence Factors Studies For Horizontal Well Production In Sandstone Reservoir

Horizontal well is a development technique which increases oil output by expanding reservoir drainage area. Compared with the vertical well, horizontal well has advantages on lower producing pressure difference and high productivity. By fully using of the advantages of restraint of aquifer ascension, saving drilling investment and enhancing oil recovery, it supplies an economical and effective development means for oil. But as the effect of geology, liquid property and etc, the production effects are greatly different. Thus, it is unable to meet the requirement of economic development.Factors which impact on the production effect of horizontal well are complex. This paper establishes reservoir model by using accurate geological modeling and numerical simulation technology. Through numerical simulation, study the impact of horizontal well parameters and reservoir parameters on production effect. Horizontal well parameters include the length of horizontal segment, the direction of horizontal wells and the position of horizontal segment on the vertical. And reservoir parameters include permeability, oil viscosity, reservoir thickness and remaining oil saturation. On the basis of single factor study, the comprehensive evaluation of the factors which affect the production effect of horizontal well is carried on by using orthogonal test. The study shows that the production effect of horizontal well is affected by reservoir characteristics, position of wells, fluid properties and other factors. As to the bottom water reservoir, horizontal well can significantly control water, and in the edge water reservoir, horizontal well has good displacement efficiency and large swept volume, thus, it is good for development. When horizontal well is parallel to the tectonic line direction, edge water evenly propel to the horizontal well. While horizontal well is perpendicular to the tectonic line direction, edge water will rush to the bottom of production well, which would obviously speed up water out, resulting in bad development effect. Development effect is good when the horizontal well in the layer is near the upper part of the reservoir and it will became bad when the horizontal well is at the top or near the bottom of the reservoir. Additionally, the more cracks the horizontal well encounters during drilling, the higher the deliverability is, and the better the development effect is. With the increase of permeability, the production effect is also improved. While with the increase of oil viscosity, it decreases instead. The production effect is better when the effective thickness is greater and the remaining oil saturation is higher. Orthogonal test indicates that the most important factor which affects the production effect of horizontal well is oil viscosity, followed by remaining oil saturation.The results have a certain theoretical value and practical significance for guiding the deployment of horizontal wells and improving the production effect of horizontal well.