2016 — Top Petroleum Engineering Diagnostics Based on Value
An overview of a few industry standard diagnostics and their pros/cons
Process /ˈpräˌses,ˈprōˌses/ noun — a series of actions or steps taken in order to achieve a particular end.
Without a doubt, a Petroleum Engineer’s playbook is massive. Processes, operations, procedures, or whatever you want to call them, are collected by the hundreds from the first day a rookie engineer steps foot into the office. With so much information ingested at a constant rate, it is easy to see how the fundamentals, however relevant they may be at the time, can become forgotten.
However, the dip and subsequent slow-rise in the price of oil has had many veteran engineers turning way back in their playbooks to find those tried and true processes with a single goal in mind: Value. The operations below are a handful of “plays” from RDS’ own engineers that they feel offer exactly that, in both cost-effectiveness and pertinent well data.
Diagnostic Fracture Injection Test (DFIT) What it is:
In it’s simplest form, a DFIT is a low-volume frac procedure (sans proppant) carried out until initial fracturing occurs. From there, pumping is ceased and the well is closed off with the intent of capturing the subsequent natural pressure decline. Since DFITs are typically carried out immediately prior to hydraulic fracturing, the only additional equipment needed to conduct the test are surface pressure gauges and flow rate meters.
What it tells you:
DFITs aide in the planning of efficient well stimulation in low-perm reservoirs that demand extensive stimulation to achieve economic production. By mimicking actual fracture conditions, several design parameters can be extrapolated from the test, such as: Reservoir Pressure, Instant Shut in Pressure (ISIP), fracture gradient, net fracture pressure, fluid efficiency, and fluid-loss coefficients.
Pros:
Minimal equipment, Invaluable data, High Value/Cost ratio
Cons:
Depending on geological conditions, DFITs may take anywhere from 2–14 days.
Offset Frac Monitoring What it is:
Offset Frac Monitoring is exactly that: monitoring the surface pressures of wells adjacent to a frac well. Whether those adjacent wells are on the same pad, or merely in the vicinity, it is good practice (and federally mandated for some) to identify any inter-well communication.
What it tells you:
Data revealing inter-well pressure interference or communication in certain zones can lead to corrective measures to prevent operational disasters and optimize well spacing, subsequently maximizing safety and production (respectively).
Pros:
Low Cost, Invaluable Data, Minimal Equipment (depending on scope of job)
Cons:
(***Editor’s Note: In all honesty, the only “downside” to this test is that it costs money at all. This is a test you should be running any time you are fracturing in proximity to adjacent wells.***)
Acoustic Well Survey What it is:
From the surface, an Acoustic Well Sounder uses sound waves created by the tool and recorded by an internal microphone to survey a designated portion of a well. When the surveys are completed, the reflections of the sound waves (or kicks) are compared to well schematics and analyzed for anomalies.
What it tells you:
Acoustic Well Surveys can yield a wide array of subsurface information: fluid level and bottom-hole pressure determination, obstruction/parted pipe location, gas lift testing, workover/completions monitoring, and barrier verification.
Pros:
Noninvasive, High Value/Cost Ratio, Invaluable Data
Cons:
Results of this test can be easily skewed/rendered unusable — conditions for surveys must be ideal and personnel performing the operation must be skilled.
Build Up Test What it is:
Usually reserved as a secondary process to be carried out during a planned shut-in, the basic procedure of a Build Up Test goes like this: install a pressure gauge to wellhead, record 15 minutes of flowing pressure data, shut the well in, and record the gradual increasing pressure until it levels off.
What it tells you:
The brilliance of this test is its simplicity and value vs. cost benefit. Although it does not garner the same attention as other tests that yield extensive well information, Build Up Tests help determine two key reservoir properties: reservoir permeability and skin damage.
Pros:
Low cost, Minimal Equipment, Invaluable data
Cons:
This test can only be carried out while well is shut in.
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Originally published at http://reservoirdata.com on June 16, 2016.
