石油学报 ›› 2013, Vol. 34 ›› Issue (6): 1040-1048.DOI: 10.7623/syxb201306002

• 地质勘探 • 上一篇    下一篇

鄂尔多斯盆地东部致密砂岩气成藏物性界限的确定

曹青1, 赵靖舟1, 刘新社2, 胡爱平2, 范立勇2, 王怀厂2   

  1. 1. 西安石油大学地球科学与工程学院 陕西西安 710065;
    2. 中国石油长庆油田公司 陕西西安 710021
  • 收稿日期:2013-05-01 修回日期:2013-08-03 出版日期:2013-11-25 发布日期:2013-10-13
  • 通讯作者: 曹青
  • 作者简介:曹青,女,1979年7月生,2002年毕业于西北大学地质学专业,2005年获西北大学矿产普查与勘探专业硕士学位,现为西安石油大学讲师,主要从事油气成藏地质学研究。Email:cao.qing@foxmail.com
  • 基金资助:

    国家重大科技专项(2011ZX05007-004)和国家自然科学基金项目(No.40902042)资助。

Determination of physical property limits for the gas accumulation in tight sandstone reservoirs in the eastern Ordos Basin

CAO Qing1, ZHAO Jingzhou1, LIU Xinshe2, HU Aiping2, FAN Liyong2, WANG Huaichang2   

  1. 1. School of Earth Sciences & Engineering, Xi'an Shiyou University, Xi'an 710065, China;
    2. PetroChina Changqing Oilfield Company, Xi'an 710021, China
  • Received:2013-05-01 Revised:2013-08-03 Online:2013-11-25 Published:2013-10-13

摘要:

为了研究鄂尔多斯盆地东部上古生界致密砂岩储层天然气充注成藏的物性界限,分析微观孔喉内天然气的受力状态,综合考虑了束缚水膜、浮力、毛细管阻力、异常超压和水动力等参数对天然气充注成藏所起的作用。将束缚水膜厚度作为天然气可充注进入致密储层的最小孔喉半径,核磁共振测试获得了岩心束缚水饱和度并据此计算了束缚水膜的厚度,综合分析得出孔喉半径下限为10 nm。利用浮力和毛细管阻力的平衡状态计算得出的临界孔喉半径作为最大孔喉半径,通过先确定主要含气层段在不同地质时期的气柱高度,据此计算得到的临界孔喉半径作为孔喉半径上限。通过常规压汞测试结果建立了孔喉中值半径与物性参数的拟合趋势,再将孔喉半径上、下限带入拟合趋势中推算得出相应的物性界限参数。物性界限推算结果为:下石盒子组八段成藏物性孔、渗参数下限分别为4% 和0.1 mD,早白垩世末期储层孔、渗参数上限分别为13% 和1.8 mD,现今储层孔、渗参数上限分别为14% 和2.0 mD;山西组二段三亚段成藏孔、渗参数下限分别为2% 和0.01 mD,早白垩世末期储层孔、渗参数上限分别为8% 和1.0 mD,现今储层孔、渗参数上限分别为9% 和1.4 mD;太原组成藏孔、渗参数下限分别为3.5% 和0.02 mD,早白垩世末期储层孔、渗参数上限分别为11% 和1.1 mD,现今储层孔、渗参数上限分别为12% 和2.0 mD。

关键词: 致密砂岩储层, 物性界限, 束缚水膜厚度, 气柱高度, 鄂尔多斯盆地

Abstract:

To determinate physical properly limits of natural gas accumulation in Upper Paleozoic tight sand reservoirs in the eastern Ordos Basin, natural gas stress condition was analyzed in micro pore throat, and irreducible water film, buoyancy, capillary resistance and abnormal high pressure and hydropower were considered for the effect of natural gas accumulation. Taking the thickness of irreducible water film as the minimum pore throat radius of tight reservoirs, it could be calculated irreducible water film and determined the lower limit of pore throat radius is equal to 10 nm based on the irreducible water saturation which measured by NMR. The maximum pore throat radius was calculated by critical pore throat radius according to equilibrium state of buoyancy and capillary resistance. To determine gas column height of main gas reservoirs at different geologic epoch, the upper limit of pore throat radius was calculated by critical pore throat radius. According to the results of mercury injection experiment, a matching tendency of the median pore throat radius and physical parameters could be established, and petrophysical limit parameters could be calculated based on generating the upper and lower limits into the tendency. The calculation results of petrophysical limits were: For the Member 8 of Lower Shihezi Formation, lower petrophysical limits of reservoir are 4% and 0.1 mD (porosity and permeability), upper petrophysical limits are 13% and 1.8 mD at the end of Early Cretaceous, and 14% and 2.0 mD at present; For 3rd sub Member of the Member 2 of Shanxi Formation, the corresponding values are, in order, 2% and 0.01 mD, 8% and 1.0 mD, 9% and 1.4 mD;For Taiyuan Formation, these are, in order, 3.5% and 0.02 mD, 11% and 1.1 mD, 12% and 2.0 mD.

Key words: tight sandstone reservoir, petrophysical limit, thickness of irreducible water film, gas column height, Ordos Basin

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