深井水平井水平段水力延伸能力评价与分析

对影响水平井水平段延伸能力的因素进行了分析，然后根据钻井液流体力学理论，建立了水平井循环压耗计算模型，分别对水平井总循环压耗和水平段环空压耗进行计算，进而求出了水平井水平段极限延伸长度值；对钻井液密度、钻井泵额定压力、岩屑床高度和钻井液排量对水平段水力延伸能力的影响进行了分析。研究表明，水平段水力延伸能力受钻井液密度、钻井泵额定压力、岩屑床高度和钻井液排量等多个因素共同影响。为了提高深井水平井的延伸能力，应使用较低密度的钻井液；尽量保持较低的岩屑床高度；钻井液排量应尽量小。同时还认识到，深井水平井水力延伸能力主要受到钻井泵额定压力的制约。研发高额定压力的钻井泵，是提高深井水平井水力延伸能力的主要措施。

The Evaluation and Analysis of Hydraulic Extensions Ability of HorizontalSection in Deep Horizontal Wells

On the basis of the theory of drilling fluid hydrodynamics，we analyzed the stress situation of horizontal section in thehorizontal well，and find that the pressure loss in the annulus space of the horizontal well and the total circulating pressure lossare of the two main factors that restricted horizontal section extension ability. In this paper，pressure loss in the annulus spaceof the horizontal well and the total circulating pressure loss in the whole borehole are calculated，and the horizontal hydraulicextensions ability value was obtained，and then the drilling fluid density，debris bed height，pump pressure and drilling fluiddelivery rate and the effect on the horizontal section extension ability was analyzed. In order to enhance the horizontal hydraulicextensions ability，we can use low mud density and the lower height of cutting bed is kept. We can draw a conclusion that wecan enhance the horizontal hydraulic extensions ability by choosing drilling pump with higher rated pump pressure.