由于致密砂砾岩具有超低渗透性,不进行水力压裂难以达到经济开采目标。砂砾岩储层的有效开采需要对水力裂缝扩展规律有清晰认识。考虑砂岩或砾岩材料本身的非均质性以及砂岩与砾岩之间的非均质性,提出一种数字图像技术和有限元软件RFPA(...由于致密砂砾岩具有超低渗透性,不进行水力压裂难以达到经济开采目标。砂砾岩储层的有效开采需要对水力裂缝扩展规律有清晰认识。考虑砂岩或砾岩材料本身的非均质性以及砂岩与砾岩之间的非均质性,提出一种数字图像技术和有限元软件RFPA(Rock Failure Process Analysis)相结合的数值模拟方法。基于该方法的致密砂砾岩压裂的二维数值模拟结果表明,在不同水平地应力差和砾岩强度条件下,水力裂缝可以穿过砾岩或沿砾岩转向扩展。考虑砾岩分布方位、尺寸和轴比,三维数值模型模拟结果表明,水力裂缝能够穿过砾岩,形成一种在常规压裂实验中不容易观察到的环绕扩展模式,也能够像二维数值模型得到的结果那样沿砾岩转向扩展,即不同的砾岩分布方位、尺寸和轴比使水力裂缝扩展遇到砾岩时呈现不同的扩展模式,包括:①直接穿过砾岩;②沿砾岩转向扩展;③环绕扩展;④模式①和②或者②和③同时出现。展开更多
Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-...Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molLl sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for 〉24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃ seawater and re-hydrated in 0.05 molL^-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.展开更多
文摘由于致密砂砾岩具有超低渗透性,不进行水力压裂难以达到经济开采目标。砂砾岩储层的有效开采需要对水力裂缝扩展规律有清晰认识。考虑砂岩或砾岩材料本身的非均质性以及砂岩与砾岩之间的非均质性,提出一种数字图像技术和有限元软件RFPA(Rock Failure Process Analysis)相结合的数值模拟方法。基于该方法的致密砂砾岩压裂的二维数值模拟结果表明,在不同水平地应力差和砾岩强度条件下,水力裂缝可以穿过砾岩或沿砾岩转向扩展。考虑砾岩分布方位、尺寸和轴比,三维数值模型模拟结果表明,水力裂缝能够穿过砾岩,形成一种在常规压裂实验中不容易观察到的环绕扩展模式,也能够像二维数值模型得到的结果那样沿砾岩转向扩展,即不同的砾岩分布方位、尺寸和轴比使水力裂缝扩展遇到砾岩时呈现不同的扩展模式,包括:①直接穿过砾岩;②沿砾岩转向扩展;③环绕扩展;④模式①和②或者②和③同时出现。
文摘Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molLl sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for 〉24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃ seawater and re-hydrated in 0.05 molL^-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.
