西南石油大学学报(自然科学版)

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Fast Coning of Bottom Water in Bioherm Oilfield of LH11 – 1

Liu Mingquan1,2, Feng Quanxiong2*, Xiao Wei3, Wu Qilin3, Dan Zhiwei3   

  1. 1. School of Resources,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China
    2. CNOOC International Limited,Dongcheng,Beijing 100010,China
    3. CNOOC EnerTech Drilling Engineering Geophysics Institute,Zhanjiang,Guangdong 524057,China
  • Online:2015-04-01 Published:2015-04-01

Abstract:

Up to now,the bioherm oilfield of LH11 – 1 is the largest uncompartmentalized one in tertiary systems in China.
In the developing period,the water cut in the different formations and structures is rising at various velocities. Although field
water-composing geological factors were analyzed before,there is still lack of understanding and recognition on the sources
of fast water-cut rise,which might severely restrict oil recovery. By the combination of sequence stratigraphy,carbonate rock
diagenesis mechanism and tectonic movement,horizontally referring to the oil-water interface planar layouts featured by G
attributes of AVO pre-stack inversion under the condition of high resolution 3-D seismic data,and vertically considering the
vp=vS obtained through pre-stack simultaneous inversion and the porosity profile of density conversion,the authors find the
ascending channels formed by multiple bottom-water piercing oil-water interface,convincingly verifying that the Karst caves
and seams created when the nearby areas surrounding the sequence interfaces between 17.5Ma and 16.5Ma get exposed,and
the fractures formed by Dongsa movement are the three sources for Fast Coning of Bottom Water in the bioherm Oilfield of
LH11 – 1. Among them,the Karst caves are the major ascending channels.

Key words: bioherm oilfield, bottom water coning, geological factors, AVO, pre-stack simultaneous inversion, karstlization