Add Sample General Info

A PVT sample has a lot of data attached to it, like compositional data, PVT experiments, but also a significant amount of additional meta data. This additional meta data is added in the General Info tab in whitson^PVT. This section is divided into three main parts defined by (1) the Note section, (2) the meta data info inputs, and (3) the summary data.

The Note section is a free form spacce where you can make notes about the sample. Typical notes that we would make is if there is something wrong in the PVT report data, some missing data, derivative data that needs to be calculated manually and is not given in the report (like the recombined mixture molecular weight).

PVT Sample Meta Data Input

The PVT sample meta data input section is a combination of different data types depending on the sample type. The different sections are (1) PVT Sample Information, (2) PVT Sample Location Information, (3) Additional Fluid Information, (4) Reservoir Conditions, and (5) PVT Sample Conditions Information.

PVT Sample Information

The data that you can enter in this section is:

Sample Name - This is a required input, that should be a unitque identifier for the sample. Examples of names that can be used are the cylinder ID, project number, or sample ID.
Sample Type - This is a required input, and is required when adding your PVT sample.
Sample Date - This is a required input, and is required when adding your PVT sample. The date can be entered by clicking on the data entry field, or by typing it in useing the date format "YYYY-MM-DD".
Well Name - This is a required input, and is required when adding your PVT sample.
Reservoir (Segment) - This is an optional input, but we highly recommend adding this. Other names for Reservoir used commonly is Field. The segment is a horizontal (sub)section of the field (for example Volve North).
Formation (Zone) - This is an optional input, but we highly recommend adding this. The zone is a vertical (sub)section of the formation (for example Hugin Central).
Fluid in Storage - This is an optional input, and is tied to a fluid in storage. Tying a PVT sample to a fluid in storage is as simple as finding the fluid in the list of fluids in storage for this fluid region.
PVT Reports - This is an optional input, and is tied to a PVT report. Tying a PVT sample to a PVT report is as simple as finding the report in the list of reports for this fluid region. We always recommend adding the PVT report (first), to tie the digatized data to the original report. You can navigate to the digital PVT report by clicking the (→) symbol. You can also download the report using the (↓) symbol.

PVT Sample Location Information

The data that you can enter in this section is:

True Vertical Depth - This is an optional input, and represents the actual depth of the sample. Not all sample types have a depth (like the separator oil samples). This data is used in the fluid property versus depth analysis!
Measured Vertical Depth - This is an optional input, and represents the measured depth of the sample. Not all sample types have a depth (like the separator oil samples).
Top Perforation Depth - This is an optional input, and represents the depth of the top of the perforation. Not all sample types have a depth.
Bottom Perforation Depth - This is an optional input, and represents the depth of the bottom of the perforation. Not all sample types have a depth.
Latitude / Longitude - This is an optional input, and represents the coordinated of where the sample was taken.

Additional Fluid Information

The data that you can enter in this section is:

Fluid Type - This is an optional input, but we highly recommend adding this. For some fluid types, this is set by default (for example, separator oils are identified as oil samples).
Mud Base - This is an optional input, and is only relevant to add if there is mud contamination in the sample. Setting this to be oil-based mud, triggers the ability to database the lab reported mud contamination level in the flashed oil and recombined fluid.

Reservoir Conditions

Laboratory reported reservoir conditions - Are they the actual reservoir conditions?

The laboratory reports often refers to the reservoir conditions, but very often these conditions are not the actual conditions in the reservoir. We recommend checking somewhere other than the PVT report to get the actual reservoir conditions.

The data that you can enter in this section is:

Reservoir Pressure - This is an optional input, but we highly recommend adding this if it is available. This data input is not available for all fluid types.
Reservoir Temperature - This is an optional input, but we highly recommend adding this if it is available. This data input is not available for all fluid types.

PVT Sample Conditions Information

How can you use the laboratory conditions to QC your sampling?

The following checks can be made to identify possible issues with your fluid samples.

Pressure when samples is much less than the reservoir saturation pressure: This results in saturated, two-phase flow. If the goal of the sampling is to get in-situ representative composition, the saturated production will most likely not give this (as the proportions might not represent what is in the reservoir).

Transport temperature is below 60C: Wax/asphaltene might drop out.

Pressure at laboratory is much less than the transport pressure and / or the sampling pressure: This might indicate that there was leakage during the transport.

Large drawdown pressure: Issues while sampling, or saturated (two-phase) production into the sampling cylinder. If the goal of the sampling is to get in-situ representative composition, the saturated production will most likely not give this (as the proportions might not represent what is in the reservoir).

The data that you can enter in this section is:

Pressure when Sampled - This is an optional input, and represents the conditions when the fluid sample was sampled.
Temperature when Sampled - This is an optional input, and represents the conditions when the fluid sample was sampled.
Transfer Pressure - This is an optional input, and represents the conditions when the fluid sample was transported from the sampling point to the laboratory.
Transfer Temperature - This is an optional input, and represents the conditions when the fluid sample was transported from the sampling point to the laboratory.
Pressure at Laboratory - This is an optional input, and represents the conditions when the fluid sample was received or opened at the laboratory.
Temperature at Laboratory - This is an optional input, and represents the conditions when the fluid sample was received or opened at the laboratory.
Sample Drawdown Pressure - This is an optional input, and represents the pressure difference (i.e. the drawdown pressure) when sampling an OFT/MDT or BHS sample.

Compositional Data Information

This section is not a data entry section, but rather a summary section for the key compositional data. This section has the following sections:

Flashed Oil Molecular Weight - Reported data entry value
Flashed Oil Density - Reported data entry value (almost always measured)
C₇₊ Watson Characterization Factor - Calculated using the back-calculated C₇₊ molecular weight and density, from the C_6- component mass amounts and component molecular weights, and the flashed oil molecular weight and density.
C₁ Molar Content - Reported data entry value
C₇₊ Molar Content - Reported data entry value
H₂S Molar Content - Reported data entry value
CO₂ Molar Content - Reported data entry value

Examples

The following examples shows what meta data can be added for some different recombined samples from different laboratory PVT reports. In general, we recommend that a combination of PVT report, and production / well data is used to give the most accurate description of the fluid data!

Example 1 - Sample CL-63169 (Duvernay)

This sample's data can be found in this PVT report. The data has been extracted for your convinience, and is summarized below. The compositional and PVT data digitalization can be found in the following sections.

PVT Sample Information

Sample Name: CL-63169
Sample Type: Recombined
Well Name: 08-05-062-24W5
Sample Date: 2013-04-14
Reservoir (Segment): Wahigan
Formation (Zone): Duvernay
Fluid in Storage: No Fluid in Storage
PVT Reports: [PVT REPORT NAME HERE]

PVT Sample Location Information

True Vertical Depth: No relevant value reported
Measured Vertical Depth: No relevant value reported
Top Perforation Depth: No relevant value reported
Bottom Perforation Depth: No relevant value reported
Latitude / Longitude: No relevant value reported

Additional Fluid Information

Fluid Type: Gas
Mud Base: No mud in system, as the sample is a surface sample!

Reservoir Conditions

Reservoir Pressure: 11168 psia (lab reported value)
Reservoir Temperature: 240.8F (lab reported value)

PVT Sample Conditions Information

Pressure when Sampled: 1030 psia (separator conditions)
Temperature when Sampled: 96.8F (separator conditions)
Transfer Pressure: No relevant value reported
Transfer Temperature: No relevant value reported
Pressure at Laboratory: No relevant value reported
Temperature at Laboratory: No relevant value reported
Sample Drawdown Pressure: Not relevant for this sample type

Example 2 - Sample 2.08+2.09 (Duvernay)

This sample's data can be found in this PVT report. The data has been extracted for your convinience, and is summarized below. The compositional and PVT data digitalization can be found in the following sections.

PVT Sample Information

Sample Name: 2.08+2.09
Sample Type: Separator Recombined
Sample Date: 2012-05-14
Well Name: 13-05-043-06W5
Reservoir (Segment): Wahigan
Formation (Zone): Duvernay
Fluid in Storage: No Fluid in Storage
PVT Reports: [PVT REPORT NAME HERE]

PVT Sample Location Information

True Vertical Depth: No relevant value reported
Measured Vertical Depth: No relevant value reported
Top Perforation Depth: No relevant value reported
Bottom Perforation Depth: No relevant value reported
Latitude / Longitude: No relevant value reported

Additional Fluid Information

Fluid Type: Gas
Mud Base: No mud in system, as the sample is a surface sample!

Reservoir Conditions

Reservoir Pressure: 7542 psia (lab reported value)
Reservoir Temperature: 106C (lab reported value)

PVT Sample Conditions Information

Pressure when Sampled: 130 psia (Sample 2.08) | 120 psia (Sample 2.09)
Temperature when Sampled: 25C (Sample 2.08) | 25C (Sample 2.09)
Transfer Pressure: 130 psia (Sample 2.08) | 3000 psia (Sample 2.09)
Transfer Temperature: 50C (Sample 2.08 and 2.09)
Pressure at Laboratory: 100 psia (Sample 2.08) | 115 psia (Sample 2.09)
Temperature at Laboratory: 21.8C (Sample 2.08 and 2.09)
Sample Drawdown Pressure: Not relevant for this sample type

Example 3 - Sample 6103-MA from well 15/9-F4 (Volve)

This sample's data can be found in this PVT report. The data has been extracted for your convinience, and is summarized below. The compositional and PVT data digitalization can be found in the following sections.

PVT Sample Information

Sample Name: 6103-MA
Sample Type: Bottomhole sample
Sample Date: 2008-05-14
Well Name: 15/9-F-4
Reservoir (Segment): Volve
Formation (Zone): Heather
Fluid in Storage: No Fluid in Storage
PVT Reports: [PVT REPORT NAME HERE]

PVT Sample Location Information

True Vertical Depth: 2928.7 mTVD (from MSL or mean sea level)
Measured Vertical Depth: 3245.5 mMD (from RKB or rotary kelly bushing)
Top Perforation Depth: No relevant value reported
Bottom Perforation Depth: No relevant value reported
Latitude / Longitude: No relevant value reported

Additional Fluid Information

Fluid Type: Oil
Mud Base: Oil-based mud

Reservoir Conditions

Reservoir Pressure: 332.8 bara (lab reported)
Reservoir Temperature: 107C (lab reported)

PVT Sample Conditions Information

Pressure when Sampled: No relevant value reported
Temperature when Sampled: No relevant value reported
Transfer Pressure: 412.65 bara
Transfer Temperature: 80C
Pressure at Laboratory: 110.04 bara
Temperature at Laboratory: 8C
Sample Drawdown Pressure: 272.7 bara

Next Steps

The next step is to add the compositional data!