Method and apparatus for identifying low permeable conglomerate diagenetic trap

Patent metadata

Field	Value
Publication number	US-11175422-B2
Application number	US-201816023226-A
Country	US
Kind code	B2
Filing date	Jun 29, 2018
Priority date	Jul 5, 2017
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

Identifying a low permeable conglomerate diagenetic trap can be implemented according to a method that comprises: determining a first relation curve between a depth and a critical physical property of a known diagenetic trap in a target work area, and a second relation curve between a reservoir physical property of the known diagenetic trap and a designated seismic attribute; determining a third relation curve between the depth and the critical physical property in the target work area and the designated seismic attribute according to the first relation curve and the second relation curve; and performing a diagenetic trap identification of the target work area according to the third relation curve. Identification accuracy of a low permeable conglomerate diagenetic trap can thereby be improved.

First claim

The invention claimed is:

1. A method for identifying a low permeable conglomerate diagenetic trap, comprising:
determining, by a processor, a first relation curve between a depth and a critical physical property of a known diagenetic trap in a target work area;
determining, by the processor, a second relation curve between a reservoir physical property of the known diagenetic trap and a designated seismic attribute;
determining, by the processor, a third relation curve between the depth and the critical physical property of the known diagenetic trap in the target work area and the designated seismic attribute according to the first relation curve and the second relation curve; and
identifying, by the processor, one or more diagenetic traps within the target work area according to the third relation curve,
wherein identifying, by the processor, the one or more diagenetic traps within the target work area according to the third relation curve comprises:
in each depth plane of the target work area, determining, by the processor, a distribution of position points where a first porosity is larger than a second porosity according to the third relation curve, so as to determine a distribution of the one or more diagenetic traps in the depth plane, wherein the first porosity is a reservoir porosity corresponding to the relative wave impedance under a depth corresponding to the depth plane and the second porosity is a critical porosity under the depth; and
determining, by the processor, a trap number of the one or more diagenetic traps within the target work area and a connectivity between the one or more diagenetic traps, based on the distribution of the one or more diagenetic traps in all of the depth planes of the target work area.

2. The method for identifying a low permeable conglomerate diagenetic trap according to claim 1 , wherein determining, by the processor, the first relation curve between the depth and the critical physical property of the known diagenetic trap in the target work area comprises:
acquiring a depth, a surrounding rock pore throat radius, a reservoir pore throat radius, and
a reservoir porosity corresponding to the reservoir pore throat radius of the known diagenetic trap;
determining, by the processor, a relation curve between the depth and a critical reservoir pore throat radius in the target work area according to the depth and a ratio of the reservoir pore throat radius to the surrounding rock pore throat radius; and
determining, by the processor, a relation curve between the depth and a critical porosity in the target work area according to the reservoir porosity and the relation curve between the depth and the critical reservoir pore throat radius.

3. The method for identifying a low permeable conglomerate diagenetic trap according to claim 1 , wherein the designated seismic attribute is a relative wave impedance, and wherein determining, by the processor, the second relation curve between the reservoir physical property of the known diagenetic trap and the designated seismic attribute comprises:
acquiring a reservoir porosity of the known diagenetic trap and corresponding relative wave impedance; and
fitting the reservoir porosity with the corresponding relative wave impedance to obtain a relation curve between the reservoir porosity and the corresponding relative wave impedance in the target work area.

4. The method for identifying a low permeable conglomerate diagenetic trap according to claim 1 , wherein the third relation curve comprises a relation curve between the critical porosity, the depth, and a relative wave impedance in the target work area.

5. The method for identifying a low permeable conglomerate diagenetic trap according to claim 2 , wherein determining, by the processor, the relation curve between the depth and the critical reservoir pore throat radius in the target work area according to the depth and the ratio of the reservoir pore throat radius to the surrounding rock pore throat radius comprises:
cross-plotting the depth with the ratio of the reservoir pore throat radius to the surrounding rock pore throat radius, and determining the relation curve between the depth and the critical reservoir pore throat radius in the target work area.

6. The method for identifying a low permeable conglomerate diagenetic trap according to claim 2 , wherein determining, by the processor, the relation curve between the depth and the critical porosity in the target work area according to the reservoir porosity and the relation curve between the depth and the critical reservoir pore throat radius comprises:
determining, by the processor, the relation curve between the depth and the critical porosity in the target work area according to a positive correlation relation between the reservoir porosity and the reservoir pore throat radius and the relation curve between the depth and the critical reservoir pore throat radius.

7. An apparatus for identifying a low permeable conglomerate diagenetic trap, comprising:
a processor; and
a memory operatively coupled to the processor and storing instructions which when executed, cause the processor to perform specific operations,
wherein the specific operations comprise:
determining a first relation curve between a depth and a critical physical property of a known diagenetic trap in a target work area;
determining a second relation curve between a reservoir physical property of the known diagenetic trap and a designated seismic attribute;
determining a third relation curve between the depth and the critical physical property of the known diagenetic trap in the target work area and the designated seismic attribute according to the first relation curve and the second relation curve; and
identifying one or more diagenetic traps within the target work area according to the third relation curve,
wherein identifying the one or more diagenetic traps within the target work area according to the third relation curve comprises:
in each depth plane of the target work area, determining a distribution of position points where a first porosity is larger than a second porosity according to the third relation curve, so as to determine a distribution of the one or more diagenetic traps in the depth plane, wherein the first porosity is a reservoir porosity corresponding to the relative wave impedance under a depth corresponding to the depth plane and the second porosity is a critical porosity under the depth; and
determining a trap number of the one or more diagenetic traps within the target work area and a connectivity between the one or more diagenetic traps, based on the distribution of the one or more diagenetic traps in all of the depth planes of the target work area.

8. The apparatus for identifying a low permeable conglomerate diagenetic trap according to claim 7 , wherein when determining the first relation curve between the depth and the critical physical property of the known diagenetic trap in a target work area, the processor further performs the following operations:
acquiring a depth, a surrounding rock pore throat radius, a reservoir pore throat radius and a reservoir porosity corresponding to the reservoir pore throat radius of the known diagenetic trap;
determining a relation curve between the depth and a critical reservoir pore throat radius in the target work area according to the depth and a ratio of the reservoir pore throat radius to the surrounding rock pore throat radius; and
determining a relation curve between the depth and the critical porosity in the target work area according to the reservoir porosity and the relation curve between the depth and the critical reservoir pore throat radius.

9. The apparatus for identifying a low permeable c

Assignees

• Petrochina Co Ltd

Inventors

• Qu Yongqiang
• Pan Jianguo
• Yin Lu
• Wang Guodong
• Xu Duonian
• Teng Tuanyu
• Wang Bin
• Qu Jianhua
• Li Dezi
• Huang Linjun
• Ma Yongping
• Chen Xuezhen

Classifications

• G01V1/306 Primary

  for determining physical properties of the subsurface, e.g. impedance, porosity or attenuation profiles · CPC title

• G01V1/282

  Application of seismic models, synthetic seismograms · CPC title

• G01V2210/6246

  Permeability · CPC title

• G01V2210/6169

  using well-logging · CPC title

• G01V2210/6244

  Porosity · CPC title