Abstract

In this paper we present the results of studies of the Botuobin, Talakh, and Khamakin reservoirs of the Vendian period in the Chayanda hydrocarbon field (Eastern Siberia). Based on an analysis of variations in the petrophysical parameters of reservoirs upon an increase in effective pressure from 37 to 57 MPa, i.e., under conditions simulating the development of a field for depletion, changes in the volume and compressibility of the pore space are estimated. In this case, the porosity coefficient decreases by 0.043 abs. %, while the compressibility of the pore space decreases by 0.228 1/GPa. The average volumetric compression strain increases by 0.096%, which means a reduction in the volume of developed reservoirs by almost 0.1% relative to the beginning of development. A deformable formation model developed by Yu.O. Kuzmin based on the geodynamic history of the development of deposits is applied to estimate the magnitude of possible subsidence of the ground surface during development. The maximal values of possible surface subsidence (drawdowns) upon a decrease in reservoir fluid pressure by 5 MPa are estimated to be 0.33 m with allowance for the dynamics of petrophysical parameters and 0.335 m with no allowance for it. The maximal drawdowns are already estimated at 0.60 and 0.65 m upon a decrease in reservoir pressure by 10 MPa and 0.78 and 0.83 m upon a complete depletion of reservoir energy, respectively. The results of the studies show that taking into account the changes in petrophysical characteristics caused by the field development processes alters the estimate of the deformation state of the rock massif and the ground surface above the deposit and, consequently, the estimate of the level of geodynamic risk of oil-and-gas complex objects.

中文翻译：

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评估 Chayanda 油田开发对地面沉降的影响

摘要

在本文中，我们介绍了 Chayanda 油气田（东西伯利亚）Vendian 时期的 Botuobin、Talakh 和 Khamakin 油藏的研究结果。通过分析有效压力从37 MPa增加到57 MPa时，即模拟油田开发枯竭的条件下，储层岩石物理参数的变化，估算了孔隙空间体积和压缩性的变化。在这种情况下，孔隙率系数降低了 0.043 绝对值。%，而孔隙空间压缩系数降低了0.228 1/GPa。平均体积压缩应变增加了0.096%，这意味着已开发储层体积相对于开发之初减少了近0.1%。Yu.O. 开发的变形地层模型 库兹明基于沉积物开发的地球动力学历史，用于估计开发过程中地表可能沉降的幅度。当储层流体压力降低 5 MPa 时，考虑到岩石物理参数的动态变化，估计可能出现的地表沉降（下降）最大值为 0.33 m，而没有考虑到动态参数，估计为 0.335 m。据估计，当油藏压力降低 10 MPa 时，最大水位下降分别为 0.60 和 0.65 m；当油藏能量完全耗尽时，最大水位下降分别为 0.78 和 0.83 m。研究结果表明，考虑到油田开发过程引起的岩石物理特征的变化，改变了对岩体变形状态和沉积物上方地表的估计，从而改变了对地球动力水平的估计油气复杂物体的风险。