Rock Stress Measurement by Hydraulic Fracturing with Hemispherical-ended Borehole

半球形钻孔水力压裂测量岩石应力

• 批准号: 03452241
• 负责人: OKAMURA Hiroshi
• 金额: $ 4.42万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452241/
• 关键词: Rock Stress Measurement; Hydraulic Fracturing; Finite Element Method; Hemispherical-ended Borehole Technique; 初期応力; 岩盤計測; 岩盤応力

Recent development in relation to prediction of structural stability of large rock cavern has indicated the need for systematic stress measurements in the field, e.g. systematic measurement of the stress distributions around caverns. In the hydraulic fracturing to determine the state stress at a certain point within a rock mass, the fracture phenomena of a borehole surface, which is a function of the field stress, needs to be measured by applying hydraulic pressure into the borehole. Hydraulic fracturing with hemispherical-ended borehole is very similar to conventional hydraulic fracturing except for the location of applying hydraulic pressure, namely the pressure at the borehole bottom surface which is formed hemispherically. This method has a possibility to measure the three dimensional stress state in rock mass in a single borehole.Firstly, hydraulic fracturing of spherical cavity in infinite rock mass is suggested. Then the fracture phenomena are analyzed by the stress coefficients determined theoretically on the surface of the cavity. It is clarified that two magnitudes and three directions of the principal stresses of rock stress are determined by this method. Secondly hydraulic fracturing with hemispherical-ended borehole is suggested and the stress coefficients are determined by FEM for analyzing fracture phenomena at borehole bottom surface. Finally, analyzing the fracture phenomena on the hemispherical-ended borehole surface under general three dimensional rock stresses, it is made clear that those are dominated by the deferential stress, the directions of principal stresses, the tensile strength of rock mass and so on. It is concluded that the rock stress can be determined by the hydraulic fracturing with hemispherical-ended borehole.

与大型岩石洞穴结构稳定性的预测有关的最新发展表明，需要在现场进行系统的应力测量值，例如系统测量洞穴周围的应力分布。在液压压裂中以确定岩体内某个点的状态应力，需要通过将液压压在井眼中施加液压压力来测量井眼表面的断裂现象。除半球端的井眼液压压裂外，除了施加液压压力的位置，即在半球形形成的钻孔底部表面上的压力非常相似。该方法有可能在单个钻孔中测量岩石质量中的三维应力状态。首先，建议在无限岩石质量中的球形腔液压破裂。然后，通过理论上在腔表面确定的应力系数分析断裂现象。澄清说，岩石应力的主要应力的两个幅度和三个方向是由这种方法确定的。其次，建议提出用半球末端的钻孔进行液压压裂，并通过FEM来确定应力系数，用于分析钻孔底部表面的断裂现象。最后，在一般的三维岩石应力下分析半球骨骼孔表面上的断裂现象，很明显，这些现象是由有尊敬的压力，主要应力的方向，岩石质量的拉伸强度等主导的。得出的结论是，岩石应力可以通过半球末端钻孔的液压压裂来确定。

项目成果

K.SUGAWARA,Y.OBARA,K.KANEKO,T.AOKI: "Hemispherical-ended borehole technigue for measurement of absolute rock stress" Proc.of INT.Symp on Rock Stress and Rock Stress Measurements. 207-216 (1986)

K.SUGAWARA、Y.OBARA、K.KANEKO、T.AOKI：“用于测量绝对岩石应力的半球端钻孔技术”Proc.of INT.Symp on Rock Stress 和 Rock StressMeasures。

K.SUGAWARA, Y.OBARA, K.KANEKO and T.AOKI: "Hemispherical-ended Borehole Technique for Measurement of Absolute Rock Stress" Proc. of Int, Symp on Rock Stress and Rock Stress Measurement. 207-216. (1986)

K.SUGAWARA、Y.OBARA、K.KANEKO 和 T.AOKI：“测量绝对岩石应力的半球端钻孔技术”Proc。

尾原 祐三,菅原 勝彦,荒木 秀郎,有賀 義明: "スリーブフラクチャリング法による岩盤応力測定" 材料. 38. 13-19 (1988)

Yuzo Ohara、Katsuhiko Sukawara、Hideo Araki、Yoshiaki Ariga：“套筒压裂法测量岩石应力”材料 38. 13-19 (1988)。

K.SUGAWARA,K.KANEKO,Y.OBARA,H.OKAMURA: "Determination of the State of Stress in Rock by the Measurement of Strains on the Hemispherical Borehole Bottom" Proc.of INT.Symp on Large Rock Caverns. 2. 1039-1050 (1986)

K.SUGAWARA、K.KANEKO、Y.OBARA、H.OKAMURA：“通过测量半球形钻孔底部应变来确定岩石中的应力状态”Proc.of INT.Symp on Large Rock Caverns。

K.Sugawara: "MEASUREMENT OF IN-SITU ROCK STRESS BY HEMISPHERICAL-ENDED BOREHOLE TECHNIQUE" Mining Science and Technology. 3. 287-300 (1986)

K.Sukawara：“通过半球端钻孔技术测量原位岩石应力”采矿科学与技术。