Analyzing reservoir using fluid analysis

Patent metadata

Field	Value
Publication number	US-2016168985-A1
Application number	US-201514966689-A
Country	US
Kind code	A1
Filing date	Dec 11, 2015
Priority date	Dec 11, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

Various implementations directed to analyzing a reservoir using fluid analysis are provided. In one implementation, a method may include determining mud gas logging (MGL) data based on drilling mud associated with a wellbore traversing a reservoir of interest. The method may also include determining first downhole fluid analysis (DFA) data based on a first reservoir fluid sample obtained at a first measurement station in the wellbore. The method may further include determining predicted DFA data for the wellbore based on the first DFA data. The method may additionally include determining second DFA data based on a second reservoir fluid sample obtained at a second measurement station in the wellbore. The method may further include analyzing the reservoir based on a comparison of the MGL data and a comparison of the second DFA data to the predicted DFA data.

First claim

What is claimed is:

1 . A method, comprising:
determining mud gas logging (MGL) data based on drilling mud associated with a wellbore traversing a reservoir of interest; determining first downhole fluid analysis (DFA) data based on a first reservoir fluid sample obtained at a first measurement station in the wellbore; determining predicted DFA data for the wellbore based on the first DFA data; determining second DFA data based on a second reservoir fluid sample obtained at a second measurement station in the wellbore; and analyzing the reservoir based on a comparison of the MGL data and a comparison of the second DFA data to the predicted DFA data.

2 . The method of claim 1 , wherein determining predicted DFA data for the wellbore based on the first DFA data comprises:
determining the predicted DFA data using one or more equations of state (EOS) models of thermodynamic behavior of reservoir fluid.

3 . The method of claim 1 , wherein determining predicted DFA data for the wellbore based on the first DFA data comprises:
determining the predicted DFA data using one or more equations of state (EOS) models of thermodynamic behavior of reservoir fluid based on the first DFA data and the MGL data.

4 . The method of claim 1 , wherein determining predicted DFA data for the wellbore based on the first DFA data comprises:
determining predicted DFA data for one or more depth locations in the wellbore.

5 . The method of claim 1 , wherein analyzing the reservoir based on the comparison of the MGL data comprises:
comparing first MGL data corresponding to the first measurement station to second MGL data corresponding to the second measurement station.

6 . The method of claim 5 , further comprising:
using a comparison of the first MGL data and the second MGL data to identify one or more causes of a non-equilibrium state of the reservoir.

7 . The method of claim 6 , wherein the one or more causes are selected from a group consisting of:
one or more geologic events altering a structure of the reservoir structure; thermally mature fluids arriving into the reservoir; hydrocarbons escaping via flow channels or a compromised cap seal of the reservoir; biodegradation and mixing with biogenic methane in the reservoir; biogenic methane arriving at the reservoir; and water washing.

8 . The method of claim 1 , wherein analyzing the reservoir based on the comparison of the MGL data comprises:
determining that the reservoir is compartmentalized and in a non-equilibrium state if the second DFA data differs from the predicted DFA data by a threshold amount.

9 . The method of claim 8 , wherein the threshold amount corresponds to an amount greater than or equal to a monotonic variation between the second DFA data and the predicted DFA data.

10 . The method of claim 1 , wherein the MGL data comprise a quantitative composition of hydrocarbons in gas extracted from the drilling mud.

11 . The method of claim 1 , wherein the MGL data comprises isotope logging data.

12 . The method of claim 11 , wherein the isotope logging data is based on spot mud gas samples of the drilling mud.

13 . The method of claim 1 , wherein the first DFA data comprise one or more measurements of gas-oil ratio (GOR), fluid composition, acidity, fluorescence, optical density, fluid resistivity, fluid density, fluid viscosity, temperature, pressure, or combinations thereof.

14 . A well site system, comprising:
one or more degassers configured to extract gas from drilling mud associated with a wellbore traversing a reservoir of interest; one or more gas analyzers configured to interact with the one or more degassers and to generate data relating to the extracted gas; one or more downhole tools configured to obtain a first reservoir fluid sample at a first measurement station in the wellbore and a second reservoir fluid sample at a second measurement station in the wellbore; one or more computing systems, comprising:
a processor; and
a memory comprising a plurality of program instructions which, when executed by the processor, cause the processor to:
determine mud gas logging (MGL) data based on the data relating to the extracted gas;
determine first downhole fluid analysis (DFA) data based on the first reservoir fluid sample;
determine predicted DFA data for the first wellbore based on the first DFA data;
determine second DFA data based on the second reservoir fluid sample; and
analyze the reservoir based on a comparison of the MGL data and a comparison of the second DFA data to the predicted DFA data.

15 . The well site system of claim 14 , wherein the program instructions which cause the processor to determine the predicted DFA data for the first wellbore based on the first DFA data further comprises program instructions which, when executed by the processor, cause the processor to:
determine the predicted DFA data using one or more equations of state (EOS) models of thermodynamic behavior of reservoir fluid.

16 . The well site system of claim 14 , wherein the program instructions which, when executed by the processor, further cause the processor to:
determine that the reservoir is compartmentalized and in a non-equilibrium state if the second DFA data differs from the predicted DFA data by a threshold amount.

17 . A method, comprising:
determining mud gas logging (MGL) data based on drilling mud associated with a first wellbore and a second wellbore both traversing a reservoir of interest; determining first downhole fluid analysis (DFA) data based on a first reservoir fluid sample obtained at a first measurement station in a first wellbore; determining predicted DFA data for the first wellbore based on the first DFA data; determining second DFA data based on a second reservoir fluid sample obtained at a second measurement station in a second wellbore; and analyzing the reservoir based on a comparison of the MGL data and a comparison of the second DFA data to the predicted DFA data.

18 . The method of claim 17 , wherein determining predicted DFA data for the first wellbore based on the first DFA data further comprises:
determining the predicted DFA data using one or more equations of state (EOS) models of thermodynamic behavior of reservoir fluid.

19 . The method of claim 17 , wherein analyzing the reservoir based on the comparison of the MGL data comprises:
comparing first MGL data corresponding to the first measurement station to second MGL data corresponding to the second measurement station.

20 . The method of claim 17 , wherein analyzing the reservoir based on the comparison of the MGL data comprises:
determining that the reservoir is compartmentalized and in a non-equilibrium state if the second DFA data differs from the predicted DFA data by a threshold amount.

Assignees

• Schlumberger Technology Corp

Inventors

• Betancourt-Pocaterra Soraya S
• Strapoc Dariusz
• Fornasier Ivan
• Mishra Vinay K
• Canas Jesus Alberto
• Mullins Oliver C

Classifications

• E21B49/005 Primary

  Testing the nature of borehole walls or the formation by using drilling mud or cutting data · CPC title