A discrepancy in your company’s crude measurement process could have a significant impact on your company. It could mean millions of dollars. It could mean lost time for the back office verifying reports. It could mean disagreements with third-parties, land owners, vendors, and stakeholders who rely on the accuracy of the product being measured.
Because there are many elements that affect your company’s ability to accurately and repeatedly measure the produced product, it is critical to maintain an auditable process to protect the integrity of your measurements.
First Point of Separation: Ensure Accurate Measurement
Crude measurement needs a starting point. Measurement begins when the product is lifted to wellhead.
However, the entire product is not crude oil. Depending on location, there could be high amounts of salt, water, sand, or other impurities produced with the oil.
Therefore, you need to be able to isolate the product from the other elements. At GCI, we teach the two-phase and three-phase separator measurement to achieve an accurate first measurement.
We also teach the importance of multi-phase flow measurement to continuously record an accurate measurement of the oil and other elements at the first point of separation.
Volume Gauging and Temperature Determination
The next important step to maintain an auditable process of crude measurement is using tools to gauge the volume of oil in the holding or storage tank.
At GCI, we teach two types of volume gauging techniques: manual volume gauging and automatic volume gauging. You will need to determine the most reliable technique for your company that can be repeated with consistency and accuracy to maintain the integrity of the measurement.
We also teach the importance of temperature determination because temperature could significantly impact the crude measurement . A lower temperature will lower the volume of the product, while a higher temperature will raise the volume of the product.
Use LACT Units to Support Temperature Determination
To account for temperature determination, make sure your team of measurement professionals understand how to use LACT units (Lease Automatic Custody Transfer units) to create an accurate measurement.
LACT units automatically measure and sample the product. The system spits out a reading or ticket that helps create a paper trail for the back office. Measurement technicians should be trained on the importance of verifying a match between the reading and the record to ensure there is no discrepancy.
Physical Property Determinations for Transport
When the product is ready to be transported, the next critical measurement takes place: the density of the oil.
Density is weight per unit of volume. This measurement changes according to the changes in pressure and temperature.
The API standard for pressure is 14.696 psi and 60 degrees Fahrenheit for temperature. This is considered the base condition for a standard amount of oil that occupies one barrel of oil. If the pressure is higher or lower, the volume would remain the same, but the mass would change.
The indicator of the lightness or heaviness of the oil is the API gravity, which is measured as the inverse of the density relative to water. This is critical because oil is bought and sold based on volume and API density at standard conditions.
- Lighter oils have a higher API gravity
- Heavier oils have a lower API gravity
Once you determine the API gravity of oil, you can use formulas to calculate density. The calculations increase the reliability of the measurement. To maintain an auditable process, your measurement technicians should record their actions making the calculation.
Meter Proving and Documenting the Full Process
An auditable process is not complete without meter proving and complete documentation.
Your company should have internal policies and procedures that outline when meters are verified for accuracy and re-calibrated to ensure the same results each time. This step is critical to be able to prove the accuracy of results if questioned by third parties, landowners, or auditors.
In addition to proving the accuracy of your meters, you need to document your process from beginning to end. It boils down to two simple questions:
- Can you verify, prove, and authenticate that your measurement is accurate?
- Can stakeholders rely on the measurement you provided?
Work with GCI To Ensure Accurate and Reliable Measurements
There are many steps in the process of accurately measuring the product coming out of the ground from the wellhead to transportation. One mistake along the trail could create audit risks.
That’s why we offer Fundamentals of Crude Measurement training for measurement technicians responsible for supporting the accurate measurement of crude. We offer a three-day training course in Houston, Texas, that ensures measurement techs return to the field with confidence to repeatedly perform their function.
When measurement techs are confident in their role, they will help you maintain an auditable process for crude measurement that reduces the risk of discrepancies, lost time, and disputes.
View our training schedule to register your measurement technicians for our next Fundamentals of Crude Measurement course. We look forward to supporting your company.
