Abstract: Geometry of artificial fractures produced by hydraulic fracturing is very important to assess stimulation effect and to study relationship between fracturing and casing damage.Study-history about artificial (hydrofracturing)fracture geometry in Daqing Oilfield was reviewed.The evidence of every conclusion about artificial fracture geometry was analyzed.Integrating research on geometry with stress-in-situ shows that Lasaxing oilfield in Daqing area is situated in a transitional zone of two stress-in-situ types, because the vertical principal stress is very near to the minimum horizontal one.In this zone,the vertical principal stress may be a minimum principal stress or an intermediate one.However,the latter are slightly dominant,especially in fractured well depth of more than 950m.It is concluded that vertical artificial fracture has a slightly higher priority over horizontal one in Daqing Oilfield.

Key words: hydraulic fracturing, vertical fracture, horizontal fracture, stress-in-situ, Daqing Oilfield

摘要： 水力压裂裂缝形态对于判断压裂增产效果及研究压裂与套管损坏的关系是极为重要的。回顾了大庆油田压裂裂缝形态研究的历史,认真分析了每一次压裂裂缝形态结论的依据与条件。对大庆长垣地应力的系统分析和研究表明,大庆喇萨杏油田的地应力状态是处于两种类型地应力的过渡带上,即垂向应力居中与最小这两者并存,且垂向应力居中比例略高。依据水力压裂的基本原理,也不难得出水力裂缝形成的垂直缝比例略大的结论。

关键词: 水力压裂, 垂直裂缝, 水平裂缝, 地应力, 大庆油田