| Up to now, steam huff and puff is an important way to explore heavy oil reservoir all around the word. However, there is a certain pressure in the horizontal well bore,which makes fluid flow from toe to end in the practical oilfield develop process, at the same time,there is a large quantity of fluid which comes from formation constantly flow to well bore.This phenomenon named as variable quality flow process. And the well bore flow regulation was affected by the reservoir percolation, they were interaction in the horizontal well bore. It exists pressure during the general production process of horizontal well, when the oil well is diluted or higher water, the pressure is usually very small along the horizontal wellbore length and basically neglected. However, for the long-distance and high-viscosity’s oil well, it exists very higher pressure in the horizontal well so that the production pressure of heel position higher than the toe position and makes fluid flow unevenly along the borehole. Even though in the homogeneous reservoir,the pressure(namely root-end effect) still exists. Namely the oil production of root position is very high and the toe position’s production is relatively small. Following these ways, it appears the phenomenon of water cone or gas cone after a period of production. As the result of shorten production life of oil well and leaving a large number of remaining oil on the horizontal end segment.In order to come true the homogeneous leak oil in the horizontal well, I advice that a project of horizontal well sectioned and pumped simultaneously. Namely, add a center cube in the horizontal well bore. So that two flow channels which in the center tube and annular space of horizontal section to exploit crude oil. But, we don’t understand the varied pressure rule of horizontal well and influence of oil well inflow after take measures of horizontal well sectioned and pumped simultaneously. Thus, we necessary to study the flow rule comes from formation and the flow characteristics of horizontal well to offer the theoretical basis that swabbing parameter optimization design.In the article, firstly, I was based on the conservation equation of quality, momentum and energy. According to the rules of oil-water two phases flow and fully considered many factors, such as the pressure drop caused by tube wall friction, acceleration, hole roughness,radial inflow of liquid and mainstream mixture. At the same time, I was established the mathematical model of horizontal wellbore flow pressure. What’s more, according to the oil-water two phases seepage mechanical theory, deduced on potential caused by reservoirin the horizontal well and the equation of formation stably seepage.Insuring the flow model of horizontal wellbore. Under satisfy conditions of pressure continuity and quality volume balance, combined with the energy conservation equation of temperature and reservoir model to established the coupling model.And then, I make a calculation program used by VB language and described the change law of pressure drop used by MATLAB software.Through comparing the pressure drop,optimized some parameters which optimum distance and diameter of center tube and so on.Finally results as followed: In order to the optimum yield, the center tube’s caliber is 4cm, depth is 118 m and increase of 2 m3/d yield.Selected the Du 84Da-H1 wells as an example,it’s an integral pump barrel of tubular pump.Among them, the pump diameter is 70 mm, plunger area is 38.48cm2,tubing outside diameter is 88.9mm,sucker rod thread diameter is 30.163 mm,pumping unit type is CYJY14-6-89 HB. |
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