Method of searching for oil-gas reservoir based on trap-3D software

Patent metadata

Field	Value
Publication number	US-10228478-B2
Application number	US-201514946466-A
Country	US
Kind code	B2
Filing date	Nov 19, 2015
Priority date	Nov 5, 2014
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

The present invention provides a method of searching for an oil-gas reservoir based on TRAP-3D software, including: establishing a three-dimensional lithology and fault data cube of an exploration working area according to three-dimensional seismic data and logging data; dividing the three-dimensional lithology and fault data cube into several depth slices of the same thickness, and performing an individual sand body unit division for each depth slice; sequentially inputting the depth slices of the three-dimensional lithology and fault data cube into the TRAP-3D software for oil-gas reservoir evaluation. The present invention improves the accuracy of three-dimensional trap evaluation, is conducive to precise searching of the oil-gas reservoir, can plot a Sweet-Spot diagram on a plane, and get exhibits oil-gas trap amounts of different depths in a longitudinal direction, and can obtain a total trap amount of the oil gas reservoir in the exploration working area.

First claim

What is claimed is:

1. A method of searching for an oil-gas reservoir based on TRAP-3D software, comprising:
establishing a three-dimensional lithology and fault data cube of an exploration working area according to three-dimensional seismic data and logging data;
dividing the three-dimensional lithology and fault data cube into several depth slices of the same thickness, and performing an individual sand body unit division for each depth slice;
sequentially inputting the depth slices of the three-dimensional lithology and fault data cube into the TRAP-3D software for oil-gas reservoir evaluation,
wherein the step of sequentially inputting the depth slices of the three-dimensional lithology and fault data cube into the TRAP-3D software for the oil-gas reservoir evaluation specifically comprises:
performing a trap evaluation automatically with a computer for respective individual sand body units in each depth slice layer by layer to obtain estimated trap amounts of the respective individual sand body units in each depth slice;
performing the following steps with a computer: plotting a Sweet-Spot diagram on a plane according to the estimated trap amounts of the respective individual sand body units in each depth slice; exhibiting oil-gas trap amounts of different depths in a longitudinal direction; and obtaining a total estimated trap amount of reserved oil and gas in the exploration working area, so as to find various traps of oil and gases in the exploration working area with improved accuracy, and provide a reference for drilling an oil well in the exploration working area based on the oil-gas reservoir evaluation; and
drilling an oil well in the exploration working area based on the oil-gas reservoir evaluation.

2. The method according to claim 1 , wherein the step of establishing the three-dimensional lithology and fault data cube of the exploration working area according to the three-dimensional seismic data and logging data specifically comprises:
establishing the three-dimensional lithology and fault data cube of the exploration working area by combining structural information and fault information obtained from the three-dimensional seismic data with lithological information obtained from the logging data.

3. The method according to claim 1 , wherein the step of performing the individual sand body unit division for each depth slice specifically comprises:
1) selecting a depth slice, and representing lithological information and fault information therein with corresponding characteristic indexes;
2) searching for all sand point groups composed of several sand points linked with each other in the depth slice according to preset searching rules for interlinked sand points, wherein a boundary of each sand point group is defined by mudstone and a fault;
3) merging the characteristic indexes of all sand points in each sand point group to serve as an individual sand body unit, and uniquely identifying each individual sand body unit;
4) repeating steps 1) to 3), until the individual sand body unit divisions for all the depth slices of the three-dimensional lithology and fault data cube are sequentially completed layer by layer.

4. The method according to claim 3 , wherein the preset searching rules for interlinked sand points comprises:
as to a sand point not adjacent to the fault, searching for adjacent sand points linked with the sand point in eight directions; and
as to a sand point adjacent to the fault, searching for adjacent sand points linked with the sand point in four directions.

5. The method according to claim 1 , wherein before performing the trap evaluation for respective individual sand body units in each depth slice layer by layer, the method further comprises:
setting an initial trap evaluation value for the respective individual sand body units in each depth slice.

6. The method according to claim 5 , wherein in the process of setting the initial trap evaluation value for the respective individual sand body units in each depth slice, the method further comprises:
if there exists an upper and lower connection relation between a sand point in a certain individual sand body unit of a current depth slice and a sand point in a certain individual sand body unit of the depth slice on its adjacent upper layer, the certain individual sand body unit of the current depth slice directly inherits the initial trap evaluation value of the certain individual sand body unit of the depth slice on the adjacent upper layer.

7. The method according to claim 5 , wherein the step of performing the trap evaluation for respective individual sand body units in each depth slice layer by layer to obtain estimated trap amounts of respective individual sand body units in each depth slice specifically comprises:
1) selecting a depth slice, and updating initial trap evaluation values of the respective individual sand body units in the depth slice according to a trap evaluation update rule and lithology opposition situations on both sides of a fault in the depth slice, so as to obtain the final trap evaluation values of the respective individual sand body units in the depth slice, and give the final trap evaluation values to respective sand points in corresponding individual sand body units;
2) obtaining an estimated trap amount of the depth slice according to the equation SS j =Sum{index i *MV i }, wherein SS j is the estimated trap amount of the j th depth slice, index i is a void volume of the i th individual sand body unit of the j th depth slice, and MV i is the final trap evaluation value of the i th individual sand body unit of the j th depth slice; and
3) repeating steps 1)-2) until the estimated trap amount of all the depth slices in the three-dimensional lithology and fault data cube are sequentially obtained layer by layer.

8. The method according to claim 7 , wherein the trap evaluation update rule comprises:
if an opposite side of the fault is mudstone, adjusting the trap evaluation values of the respective individual sand body units according to different smearing and sealing effects of the mudstone of the respective individual sand body units in each depth slice;
if an opposite side of the fault is sandstone, when the trap evaluation value of the individual sand body unit on the side of the fault in each depth slice is higher than that of the individual sand body unit on the opposite side of the fault, a trap evaluation leakage value is calculated in the following equation:
LEAK= DDMV *( YXZH )/SEAL/4

wherein, LEAK is the trap evaluation leakage value, DDMV is a difference between the trap evaluation values of the individual sand body units on both sides of the fault, YXZH is a sum of lithologic indexes of the trap evaluation values of the individual sand body units on both sides of the fault, and SEAL is a leakage coefficient.

Assignees

• China Nat Petroleum Corp
• Bgp Inc China Nat Pet Corp

Inventors

• Li Qingzhong
• Zhang Libin
• Zhang Xiaomin

Classifications

• G01V1/50

  Analysing data · CPC title

• G01V1/345

  Visualisation of seismic data or attributes, e.g. in 3D cubes · CPC title

• E21B43/00

  Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) · CPC title

• G01V1/302 Primary

  in 3D data cubes · CPC title

• G01V1/30

  Analysis (G01V1/50 takes precedence) · CPC title