Petroleum Goodies

Saturday, November 17, 2012

Petroleum Goodies: Calculate Daily Step Rate from Production Volume

Calculate Daily Step Rate from Production Volume

Posted: 16 Nov 2012 09:00 PM PST

Imagine you have producing gas wells with small amount of liquid production oil or water. Your liquid productions are not producing continuously (intermittent). Your liquid productions are not tied in directly to sales line. Or your wells are located far away from central facilities. Consequently, liquid productions need to be hauled by truck every certain day or every week. As a result, your production data is not in daily rate but in volume collected from certain days.

As petroleum engineer, you want to have daily production data from this volume to do production analysis or put them into simulation for history matching. You can convert this volume into step daily rate by dividing the volume with number of elapsed days when you collect the liquid production. You can calculate daily rate manually in Excel sheet or use this Excel tool to get daily step rate. This Excel tool can calculate daily step rate from production volume automatically.

Production volume can be collected in different time intervals of day, not necessary every 5 days, every week, etc. For example, you collect your liquid production every 3 days for the first month of production, every week for the second month of production then every month for the rest of your well life. This Excel tool can calculate daily step rate from production volume from different time intervals of day.

How to use this tool?

Input date in column B and your production volume in column C. Please remember, this should be production volume NOT rate. Daily step rate will be calculated in this Excel tool.
Hit Calculate button to convert production volume to daily step rate.
Check total cumulative volume from production volume and step rate for QC purposes. These two numbers should match.

Using VBA macro? Yes Note: There is a file embedded within this post, please visit this post to download the file.

Disclaimer: This work falls under the GNU General Public License. Any usage of these Excel sheets is undertaken at users own risk. There is no warranty, that they will not cause damage to your computer system, network, software or other technology. This Excel tool has VBA macro that is currently not working on Microsoft Excel for Mac OS X due to unresolved issue.Related Posts:

Sunday, September 2, 2012

Petroleum Goodies: Modified Hyperbolic Decline Curve

Modified Hyperbolic Decline Curve

Posted: 02 Sep 2012 04:10 AM PDT

Modified Hyperbolic Decline Curve Formula

Extrapolation of hyperbolic declines over long periods of time frequently results in unrealistically high reserves. To avoid this problem, it has been suggested (Robertson) that at some point in time, the hyperbolic decline be converted into an exponential decline.⁽¹⁾

This Excel tool is useful to forecast a gas well from historical production. Historical productions are used to history match to get decline parameters such as initial rate (qi), decline rate (D) and b value. A value of b = 0 corresponds to exponential decline. A value of b = 1 is called harmonic decline. Sometimes, values of b > 1 are observed. This forecasting tool is built using two decline schedules, the first schedule used hyperbolic decline (b > 1) and the second part utilized exponential decline (b = 0). The change in decline type is indicated by switch rate. Decline conversion from effective to nominal (vice versa) has been calculated in this tool.⁽²⁾

Feel free to use this tool and don’t forget to Like it and share it with your friends.

Using VBA macro? No

References:

Fekete Decline Curve Analysis
Schlumberger Oil Field Manager (OFM)

Note: There is a file embedded within this post, please visit this post to download the file.

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Thursday, February 2, 2012

Petroleum Goodies: Horizontal Well Landing Position

Horizontal Well Landing Position

Posted: 02 Feb 2012 05:08 AM PST

Visualize Horizontal Well Landing Position Easily

horizontal well landing position

This is an extended work from the previous tool called Horizontal Toe Direction posted in this website earlier. The objective of this tool is to visualize horizontal well landing position within target zone using horizontal well deviation survey and top and bottom formation data points. Once we plot these survey and tops formation data, we can determine the following information:

Horizontal length
Toe direction
Formation thickness along wellbore
Landing position within target zone
Average depth of horizontal section

How to use:

Select well you want to analyze using scroll button or alternatively, type Well Number (not Well Code) in yellow cell.
Use “Run Batch” button to run multiple well selections.
Update your well list if you have new survey data added from new well.

How to update/change database:

Put your survey data into sheet “Survey”. Required colums: Well Code, Well Name, MD, TVD, DIP, TVDSS, X COORD, Y COORD. Please put them to the same column like in this tool.
Put your top formation into sheet “Top Fromation” and your bottom formation into “Btm Fromation”. These are X-Y-Z data points, Z in TVD subsea.
Enjoy the tool!

Assumptions:

Assumptions may vary depending your needs. The following assumptions apply to the tool.

Horizontal length – calculated from heel to toe. heel defines where dip start >88 deg. This also applies to define category for well landing position and toe direction.
Formation thickness – the distance between top and bottom formations.
Landing position – calculated from average depth of horizontal section related to top and bottom formation. Available for 3 positions (i.e., top, middle, bottom), also for 5 positions.
Toe direction – calculated from average dip of horizontal section from heel to toe. Dip ranges between 90 +/-0.5 deg is called flat.

Version Updates:

Version 1:

First release Feb 2012
Works well with Excel 2003, need some modification in macro to work with Excel 2007.
You need to use Excel 2007 if your data exceed 65000 rows.

Note:

All data provided in this tool are not real data and not related to any company.
To enable copy from Excel range to Powerpoint, you have to add Ms. PowerPoint object library from VBA editor. Click Tools – References and select Microsoft PowerPoint Object Library as shown below, then hit OK. See previous Excel tool that shows you how to add this object library.

Using VBA macro? Yes

Note: There is a file embedded within this post, please visit this post to download the file.

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