岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
10期
2869-2876,2928
,共9页
水压致裂%室内试验%不同压裂介质%压力特征参数
水壓緻裂%室內試驗%不同壓裂介質%壓力特徵參數
수압치렬%실내시험%불동압렬개질%압력특정삼수
hydraulic fracturing%laboratory experiment%different fracture medium%pressure characteristic parameter
为研究不同压裂介质影响下的绝对应力测值，利用大尺寸真三轴模拟水压致裂试验系统，用清水及密度分别为1.1、1.2、1.3、1.4 g/cm3的泥浆介质对400 mm×400 mm×400 mm的花岗岩试样进行了水压致裂室内试验，成功获取了连续的压力-时间曲线。利用6种方法识别压力-时间曲线的闭合压力点，与实加最小水平主应力（ Sh =5 MPa）对比，得出单切线等4种方法较为符合实际情况；在考虑试验系统柔度影响前提下，对比了实测和理论重张压力；最后分析了在持续泵压作用下岩石裂缝延伸的压力。试验结果表明，密度为1.1、1.2 g/cm3的泥浆介质对压力特征参数的取值影响较小，误差不超过1 MPa，但密度为1.3、1.4 g/cm3的泥浆介质对特征参数值影响很大。试验结果对水压致裂地应力测量技术在不同压裂介质影响下的适用性有重要的指导意义。
為研究不同壓裂介質影響下的絕對應力測值，利用大呎吋真三軸模擬水壓緻裂試驗繫統，用清水及密度分彆為1.1、1.2、1.3、1.4 g/cm3的泥漿介質對400 mm×400 mm×400 mm的花崗巖試樣進行瞭水壓緻裂室內試驗，成功穫取瞭連續的壓力-時間麯線。利用6種方法識彆壓力-時間麯線的閉閤壓力點，與實加最小水平主應力（ Sh =5 MPa）對比，得齣單切線等4種方法較為符閤實際情況；在攷慮試驗繫統柔度影響前提下，對比瞭實測和理論重張壓力；最後分析瞭在持續泵壓作用下巖石裂縫延伸的壓力。試驗結果錶明，密度為1.1、1.2 g/cm3的泥漿介質對壓力特徵參數的取值影響較小，誤差不超過1 MPa，但密度為1.3、1.4 g/cm3的泥漿介質對特徵參數值影響很大。試驗結果對水壓緻裂地應力測量技術在不同壓裂介質影響下的適用性有重要的指導意義。
위연구불동압렬개질영향하적절대응력측치，이용대척촌진삼축모의수압치렬시험계통，용청수급밀도분별위1.1、1.2、1.3、1.4 g/cm3적니장개질대400 mm×400 mm×400 mm적화강암시양진행료수압치렬실내시험，성공획취료련속적압력-시간곡선。이용6충방법식별압력-시간곡선적폐합압력점，여실가최소수평주응력（ Sh =5 MPa）대비，득출단절선등4충방법교위부합실제정황；재고필시험계통유도영향전제하，대비료실측화이론중장압력；최후분석료재지속빙압작용하암석렬봉연신적압력。시험결과표명，밀도위1.1、1.2 g/cm3적니장개질대압력특정삼수적취치영향교소，오차불초과1 MPa，단밀도위1.3、1.4 g/cm3적니장개질대특정삼수치영향흔대。시험결과대수압치렬지응력측량기술재불동압렬개질영향하적괄용성유중요적지도의의。
To study absolute rock stress measurement under different fracture media, by using large chamber true triaxial hydraulic-pressure fracture simulating system, a hydraulic fracturing experiment in lab is carried out with 400 mm×400 mm× 400 mm granite specimen on effect of the water and the relative densities of 1.1 g/cm3, 1.2 g/cm3, 1.3 g/cm3, 1.4 g/cm3 respectively, the continuous pressure-time curves are obtained. By using 6 kinds of methods, closure pressure points on pressure-time curve are distinguished; 4 kinds of methods, for example single tangent, are consistent with actual situation through contrasting the actual minimum horizontal principal stress ( Sh =5 MPa). Considering the effect of experimental flexibility, the measured reopening pressure and theoretical reopening pressure are contrasted. Finally, the pressure of extended rock fissures in continuous pumping pressure is analyzed. The experimental results show that the slurry relative densities of 1.1 g/cm3, 1.2 g/cm3 have little effect on pressure characteristic parameters;and its error is no more than 1 MPa;the slurries with relative densities of of 1.3 g/cm3, 1.4 g/cm3 have great effect on values of pressure characteristic parameters. The experimental results have an important guiding meaning for application of hydraulic fracturing technology to measurement of absolute stress under different fracture media.
