Petroleum Engineering PROJECT (Formation Evaluation)

PNGE 450 Formation Evaluation Project

Due: Dec. 11th, 4:00pm

A well is assigned to you and you can find your assigned well name on ecampus. As a petroleum engineer, your final goal is to find hydrocarbon zones, analyze and determine the properties of these zone. Also, for all other zones, a brief lithology description should be provided with REASONING. To complete the project, you can have to use Petra as well logging software. Follow this road map and complete the project: LAS and log header data of a well is provided to you.

1) Open the files and read the values and record them for yourself: a) Total Depth of logged interval b) Max. recorded Temperature c) Mud and Mud filtrate resistivity d) Average annual surface Temp. is 65°F.

2) In the LAS file the interval of logging interpretation for you is specified (Begin and End tops). Using GR, SP, Induction, porosity, sonic logs, add necessary tops. You may name the tops numerically in order of T1, T2, … Tt is your decision how many tops are required, but do not be picky about the zonation and the number of the zones!

3) Identify clean and shale zones. For simplicity assume if shale volume is less than 20% it is

clean, and if shale volume is above 20%, it is shale and no shaliness correction is required.

4) Among the clean zones, detect permeable zones and possible hydrocarbon ones.

5) Among the clean, porous and permeable zones, select a clean, thick, water bearing zone and calculate Rw of the zone from SP log. You can use the spreadsheet. No SP to SSP correction is required.

6) Calculate the RW form another method (Pickett plot or sonic tool, Rwa) and compare it with Rw calculated through SP method. Are different method results consistent with each other? Explain.

7) Calculate the water saturation and BVW for possible hydrocarbon zones. Assume deep induction resistivity (RT90) reads Rt and no correction is required.

8) Identify pay zones with cut-off value of Sw=50%, Ø=7%, BVW<0.09, Thickness ≥ 2 ft. Core

analysis of several adjacent wells suggests the following rock properties: a=0.80, m=n=2.

9) In the hydrocarbon zones, identify the type of HC (oil or gas), also determine the WOC, WGC, GOC depths if applicable to your well.

PNGE 450

Formation Evaluation Project Due: Dec. 5th, 4:00pm

10) In the HC zones, correct the porosity for oil and/or gas effect.

11) In the HC zones, calculate the moveable HC saturation. Assume Sxo = (Sw)1/5.

12) For all the zones, identify lithology by using Neutron-Density, Rhomaa-Umaa, and Sonic-

Neutron cross plots. Then, make a decision for the lithology. For identifying the lithology of each zone, include the cross plot and the following table in the report and write down your reasoning below or on the plot. In your report, when you want to show the lithology of each zone, bring a CLEAR portion of that zone and write the lithology on the log similar to the example on slide 8 of crossplots lecture notes.

Lithology Zone Depth interval Neutron-Density Neutron-Sonic Umaa-ρmaa Your Decision

1 2 … n

Report Format:

1) Cover Page: Make sure to write the number of the well assigned to you.

2) Executive Summary: including the productive zones depths with average porosity, Sw,

and BWV of each productive zone, HC type and the total pay thickness of the well.

3) Methodology: A brief explanation of step by step process (max 2 pages)

4) Analysis and Results

5) Conclusion Important Notes:

1) Total report should NOT be more than 25 pages.

2) For HC zones, prepare and show complete set of logs including GR, resistivity, porosities,

Vsh, SW, and BVW similar to the Slide 39 of Cross plot lecture notes.

3) For simplicity, assume the Rw is constant along the well.

4) All porosities are reported in Limestone scale.

5) If a log value reads -999.25, it is a NULL number (the measurement does not exist).

6) The bit size is 7.875 inch.

7) Some logs might have alias names like LL3 which is the same as SFL. Read the log names

description in the LAS file.