第40
卷第1
期
2018
年1
月石油实验地质
PETROLEUM
GEOLOGY &
EXPERIMENTV
〇1.40,N
〇.1
Jan. ,2018
文章编号
：100
卜6112
(2018
)0
卜0078-12doi
：10.1178L/sysydz201801078
四川盆地焦石坝地区五峰|龙马溪组页岩
元素地球化学特征及对页岩气开发的意义
甘玉青，王超，方栋梁，杨兰芳，周新科，张萍
(
中国石化江汉油田分公司勘探开发研究院，武汉430223)
摘要
:选择四川盆地焦石坝地区JYAJYD
两口井的85
块页岩岩心样品，进行了有机碳和主、微量元素测试分析。通过分析主、微
量元素在剖面上的纵向变化特征，对焦石坝地区五峰组一龙马溪组含气页岩的氧化还原条件和古生产力状况进行了研究,讨论了
五峰组一龙马溪组有机质富集的主控因素;
探讨了地球化学元素对页岩可压性的影响和含气性的指示。研究区五峰组一龙马溪组
下部优质气层段有机质含量高，平均值为3.07%
。与含气页岩段相比,
优质气层段页岩中的SiO:
和CaO
含量较高,Mo
、&
、V
、Ni、Th
和L
等氧化还原敏感元素富集。V/0
、V/Sc
、L/Th
和Ni/Co
等氧化还原条件判别指标表明，五峰组沉积期以缺氧一贫氧环境为
主，龙马溪组沉积期下部以缺氧环境为主，往上则主要为含氧环境。古生产力指标Ba(
、s)
指示五峰组一龙马溪组页岩沉积期具有
高等生产力背景。优质气层段有机碳含量与Mo/A1
、L/Th
、N^Co
、V/
〜值之间存在明显的正相关,说明有机质富集主要受氧化
还原条件控制。另外，优质气层段页岩生物成因的硅质含量高，且有机碳含量与Si
〇2
含量呈正相关,有利于形成天然裂缝和后期
人工压裂改造。优质气层段的地化元素比值明显高于含气页岩段，说明化学元素比值与页岩含气性之间存在一定的相关性。
关键词
：主、微量元素；有机质富集;
可压性;
含气性;
页岩;
五峰组一龙马溪组;焦石坝地区
中图分类号
:TE122.113
文献标识码
:A
Element geochemical characteristics of the Wufeng-Longmaxi shale in
Jiaoshiba area，Sichuan Basin and their significance to shale gas development
GAN
Yuqing，WANG
Chao,
FANG
Dongliang，YANG
Lanlang，ZHOU
Xinke，ZHANG
Ping
(Research Institute of Petroleum, Exploration and Development，SINOPEC Jianghan, Oilfield Company
，Wuhan，Hubei 430223
，China)
Abstract
：
A
total
ol 85
shale
core
samples
from
wells
JYA
and
JYD
in
Jiaoshiba
area
ol
Sichuan
Basin
were
selected
to
test
their
organic
carbon
contents，major
and
trace
elements.
The
redox
conditions
and
paleoproductivity
ol
the
gas
bearing
shale
in
the
Wufeng-Longmaxi
formations
in
the
Jiaoshiba
area
were
studied
by
analyzing
the
vertical
variation
characteristics
ol
the
major
and
trace
elements
in
the
profile.
Meanwhile，the
controls
for
organic
matter
enrichment
in
the
Wufeng-Longmaxi
formations
were
explored.
Moreover，the
impact
ol
geochemical
elements
on
shale
compressibi
lity
and
gas-bearing
property
were
studied.
The
organic
carbon
content
in
the
high
gas-bearing
interval
lrom
the
Wuteng
Formation
to
the
lower
part
ol
Longmaxi
Formation
is
high
with
an
average
value
ol 3.07%.
Compared
with
the
common
gas-bearing
shale，
Si〇
2
and
CaO
contents
are
higher
in
the
high
gas-bearing
shale，
and
redox-sensitive
elements
such
as
Mo，
Cr，
V，
Ni，Th
and
U
are
enriched.
The
redox
condition
indicators
such
as
V/
Cr，
V/
Sc，
U/Th
and
Ni/Co
indicated
that
the
Wuleng
Formation
was
mostly
deposited
in
suboxic
to
anoxic
conditions，whereas
the
anoxic
environment
dominated
during
the
early
sedimentary
stage
ol
L^)ngmaxi
shale
and
evolved
into
aerobic
condi
tions
later
on.
The
contents
ol
biological
productivity-related
element
Ba(^s)
reflected
a
high
paleoproductivity，whereas
TOC
content
has
an
obvious
positive
correlation
with
redox
proxies (
Mo/
Al，
U/
Th，
Ni/Co
and
V/
Sc)
in
the
high
gas-bearing
interval，suggesting
that
the
enrichment
ol
organic
matter
was
predominantly
controlled
by
redox
environ
ment.
In
addition，the
biogenic
siliceous
content
ol
high-quality
gas-bearing
shale
is
high，and
the
organic
carbon
con
tent
is
positively
correlated
with
the
Si〇
2
content，which
is
conducive
to
the
lormation
ol
natural
lractures
and
the
later
artilicial
lracturing.
The
ratio
ol
geochemical
elements
in
the
high
gas-bearing
interval
is
signilicantly
higher
than
that
ol
common
interval，indicating
that
there
is
a
certain
correlation
between
chemical
element
ratios
and
shale
gas.
Key
words
：
major
and
trace
elements；
organic
matter
enrichment;
compressibility;
gas-
bearing；
shale;
Wuleng-
Longmaxi
formations;
Jiaoshiba
area
收稿日期
：2017-10-13;
修订日期
：2017-12-27
。
作者简介
:甘玉青（1981 —
），女，硕士，工程师,
从事油气藏地质评价工作。E-mail:iamagaii@126.com
基金项目
：国家科技重大专项（2016ZX05060)
和中国石化科技项目（P17014-3)
资助
。