Compaction of smectite-rich mudstone and its influence on pore pressure in the deepwater Joetsu Basin, Sea of Japan
Compaction of smectite-rich mudstone and its influence on pore pressure in the deepwater Joetsu Basin, Sea of Japan
复制标题
日本海上越盆地深水区富蒙脱石泥岩压实及其对孔隙压力的影响
DOI：
10.1016/j.marpetgeo.2016.07.011
复制
发表时间：
2016
影响因子：
4.2
通讯作者：
S. Imahori
中科院分区：
文献类型：
--
作者：
B. Nguyen;M. Kido;Naoki Okawa;Han Fu;Satoshi Kakizaki;S. Imahori
孔隙压力预测是日本海深水钻井的必要条件，因为根据过去的经验，浅层超压可能会导致钻井问题。“Joetsu盆地”区域位于日本海东部边缘佐渡岛西南近海。新近系沉积序列主要为浊积岩，含富蒙脱石泥岩。研究区超压形成的原因可能是机械不平衡压实作用和化学压实作用的综合作用，尤其是蒙脱石的伊利化作用。利用一维和三维PetroMod软件建立盆地模型并进行数值模拟，清晰了解下上新世士雅组和中-上中新统Teradomari组流体流动和超压发育历史。采用一种含机械压实和化学压实的富蒙脱石沉积物压实模型进行孔隙压力标定。我们研究了三个关键关系：孔隙度-有效应力、孔隙度-渗透率和蒙脱石-伊利石转化动力学。我们确定了这些关系中参数值的范围，以便在测量和模拟孔隙压力之间获得良好的拟合。结果表明，下Teradomari层和上Teradomari层的高孔压形成时间分别为8.5 Ma和5.5 Ma。自1 Ma以来，由于更新世haizme组的高沉积速率和下上新世- shiya组和中至上中新世- Teradomari组的蒙脱石-伊利石转化，所研究构造的孔隙压力大约增加了一倍。在三种情况下（高情况、极可能情况和低情况），释雅、上、下Teradomari组的超压分别小于1 MPa、15 Ma和30 Ma。研究结果可为“若越盆地”及其他地质条件相似的深水、高沉积速率、高地温梯度、富蒙脱石等盆地的未来井规划提供依据。
Pore pressure prediction is needed for drilling deepwater wildcats in the Sea of Japan because it is known from past experience that there can be drilling problems can arise due to overpressure at shallow depths. The “Joetsu Basin” area is located offshore to the southwest of Sado Island on the eastern margin of the Sea of Japan. The sedimentary succession of the Neogene is mainly composed of turbidite sediments which contained smectite-rich mudstones. The cause of overpressure in the study area is expected to be a combination of mechanical disequilibrium compaction and chemical compaction, especially from the illitization of smectite.We have constructed basin models and performed numerical simulations by using 1D and 3D PetroMod to understand clearly the history of fluid flow and overpressure development in the lower Pliocene Shiya Formation and Middle to Upper Miocene Teradomari Formations. A compaction model coupled with both mechanical and chemical compaction for smectite-rich sediments is used for pore pressure calibration. We have examined three key relationships: porosity-effective stress, porosity-permeability, and the kinetics of smectite-illite transformation. We determined the ranges for the parameter values in those relationships that allow a good fit between measured and modelled pore pressures to be obtained. Results showed that for the most likely case, high pore pressure in the Lower and Upper Teradomari developed since 8.5 Ma and 5.5 Ma, respectively. Pore pressures in studied structures have approximately doubled since 1 Ma due to the high deposition rate of the Pleistocene Haizume Formation and smectite-illite transformation in the lower Pliocene-Shiya and Middle to Upper Miocene- Lower and Upperr Teradomari formations. In three cases (high case, most likely case and low case), the overpressures in the Shiya, Upper and Lower Teradomari Formations are less than 1 MPa, 15 and 30 Ma, respectively.The results provide a basis for planning future wells in the “Joetsu Basin” area and in other basins where geological conditions are similar, i.e., deepwater, high sedimentation rate, high geothermal gradient and smectite-rich sediments.
DOI：
10.2204/iodp.sp.308.2005
发表时间：
2005-04
期刊：
--
影响因子：
--
作者：
P. B. Fleming;I. Behrmann;T. Davies;C. John
通讯作者：
P. B. Fleming;I. Behrmann;T. Davies;C. John
影响因子：
4.2
作者：
N. Binh;T. Tokunaga;T. Nakamura;K. Kozumi;M. Nakajima;M. Kubota;H. Kameya;M. Taniue
通讯作者：
N. Binh;T. Tokunaga;T. Nakamura;K. Kozumi;M. Nakajima;M. Kubota;H. Kameya;M. Taniue