Petroleum Science >2015, Issue 4: 606-617 DOI: https://doi.org/10.1007/s12182-015-0058-1
Geological characteristics and ‘‘sweet area’’ evaluation for tightoil Open Access
文章信息
作者：Cai-Neng Zou and Zhi Yang
作者单位：
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China;PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
投稿时间：2015-05-11
引用方式：Zou, CN., Yang, Z., Hou, LH. et al. Pet. Sci. (2015) 12: 606. https://doi.org/10.1007/s12182-015-0058-1
文章摘要
Tight oil has become the focus in exploration
and development of unconventional oil in the world,
especially in North America and China. In North America,
there has been intensive exploration for tight oil in marine.
In China, commercial exploration for tight oil in continental
sediments is now steadily underway. With the discovery
of China’s first tight oil field—Xin’anbian Oilfield
in the Ordos Basin, tight oil has been integrated officially
into the category for reserves evaluation. Geologically,
tight oil is characterized by distribution in depressions and
slopes of basins, extensive, mature, and high-quality source
rocks, large-scale reservoir space with micro- and nanopore
throat systems, source rocks and reservoirs in close contact
and with continuous distribution, and local ‘‘sweet area.’’
The evaluation of the distribution of tight oil ‘‘sweet area’’
should focus on relationships between ‘‘six features.’’
These are source properties, lithology, physical properties,
brittleness, hydrocarbon potential, and stress anisotropy. In
North America, tight oil prospects are distributed in
lamellar shale or marl, where natural fractures are frequently
present, with TOC[4 %, porosity[7 %, brittle
mineral content[50 %, oil saturation of 50 %–80 %,
API[35 , and pressure coefficient[1.30. In China, tight
oil prospects are distributed in lamellar shale, tight sandstone,
or tight carbonate rocks, with TOC[2 %, porosity[
8 %, brittle mineral content[40 %, oil saturation of
60 %–90 %, low crude oil viscosity, or high formation
pressure. Continental tight oil is pervasive in China and its
preliminary estimated technically recoverable resources are
about (20–25) 9 108 t.
and development of unconventional oil in the world,
especially in North America and China. In North America,
there has been intensive exploration for tight oil in marine.
In China, commercial exploration for tight oil in continental
sediments is now steadily underway. With the discovery
of China’s first tight oil field—Xin’anbian Oilfield
in the Ordos Basin, tight oil has been integrated officially
into the category for reserves evaluation. Geologically,
tight oil is characterized by distribution in depressions and
slopes of basins, extensive, mature, and high-quality source
rocks, large-scale reservoir space with micro- and nanopore
throat systems, source rocks and reservoirs in close contact
and with continuous distribution, and local ‘‘sweet area.’’
The evaluation of the distribution of tight oil ‘‘sweet area’’
should focus on relationships between ‘‘six features.’’
These are source properties, lithology, physical properties,
brittleness, hydrocarbon potential, and stress anisotropy. In
North America, tight oil prospects are distributed in
lamellar shale or marl, where natural fractures are frequently
present, with TOC[4 %, porosity[7 %, brittle
mineral content[50 %, oil saturation of 50 %–80 %,
API[35 , and pressure coefficient[1.30. In China, tight
oil prospects are distributed in lamellar shale, tight sandstone,
or tight carbonate rocks, with TOC[2 %, porosity[
8 %, brittle mineral content[40 %, oil saturation of
60 %–90 %, low crude oil viscosity, or high formation
pressure. Continental tight oil is pervasive in China and its
preliminary estimated technically recoverable resources are
about (20–25) 9 108 t.
关键词
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Tight oil Geological features ‘‘Sweet area’’evaluation Tight reservoirs Unconventional oil and gas Shale oil