摘要
有关疏松砂岩油藏水平井塑性破坏半径的研究没有考虑高温交变应力对近井岩石塑性破坏过程的影响.分析热采复杂条件下的水平井近井地层应力分布规律,提出基于不同岩石破坏准则的近井塑性破坏半径预测方法.结果表明,井壁处的塑性屈服函数值越大,井壁破坏程度越大,出砂越严重,塑性屈服函数的零点即为塑性破坏半径.井底温度越高,塑性破坏半径越大.塑性破坏半径受原地主应力顺序、井周角、方位角、井底流压等因素影响.当垂向主应力大于水平主应力时,垂直方向上的塑性破坏半径最大;反之,水平方向上的塑性破坏半径最大.当水平井方位角为0°(或180°)时,井周塑性破坏半径最大;当水平井方位角为90°(或270°)时,井周塑性破坏半径最小.该研究成果对于热采水平井出砂预测有一定的指导意义.
Since previous plastic radius prediction model for horizontal wells have ignored the HTHP effect under thermal recovery conditions.A new model to calculate plastic radius near around the wellbore due to thermal recovery wells was proposed in this paper,based on different rock failure criterions.It was proved that with the increase of plastic yield function value at the surface of wellbore,the extent of the wellbore damage increased,and more serious sanding trend followed;Null point of plastic yield function was defined as the outer boundary of the plastic yielding zone,term plastic yielding radius,which is the measurement of sanding zone.Yielding radius increased with the temperature elevation.It has been seen from the analyses of numerical example that order of in situ stress,circumference angle,azimuth angle and injecting pressure are the main factors of plastic yielding radius.More specifically,whenσv>σH,vertical plastic radius become larger than that of horizontal directions while it is just on the opposite whenσv<σH.Plastic yielding radius become largest while the maximum horizontal in situ stress is paralleled to wellbore axis,while comes to its contrary while the maximum horizontal in situ stress and wellbore axis are orthogonal with each other.The research result may have some guiding significance on sanding prediction for thermal horizontal wells.
出处
《东北石油大学学报》
CAS
北大核心
2014年第5期103-110,11,共8页
Journal of Northeast Petroleum University
基金
国家自然科学基金项目(51374226)
关键词
塑性破坏半径
出砂预测
热采
水平井
近井应力
出砂半径
plastic yielding radius
sanding prediction
thermal recovery
horizontal well
crustal stress around wellbore
sanding radius
作者简介
李彦龙（1989-）,男,硕士研究生,主要从事油气井防砂完井、固液多相流方面的研究.
