Question

Identify the following well test methods corresponding to the transient pressure profiles in the figures given below. (BHP: Bottom-hole pressure, BOPD: Barrels of oil per day) 
 

• A. P – IV, Q – II, R – I, S – III
• B. P – II, Q – III, R – IV, S – I
• C. P – II, Q – III, R – I, S – IV
• D. P – IV, Q – I, R – III, S – II

Hint:

Each well test method provides insights into different aspects of reservoir behavior: pressure decline, production interference, and well productivity.

Answer 1

The Correct Option is C

We are given four transient pressure profiles corresponding to different well test methods. Let's go over each profile and match it with the appropriate well test method: - Profile (I): The plot shows a well flow rate that stabilizes at a certain value after an initial drop. This is characteristic of a Flow-after-flow test (R), which is typically used to analyze pressure decline over time as the well is produced. This test involves a continuous production followed by monitoring of the pressure response at the observation well. Hence, R corresponds to Profile (I). - Profile (II): The pressure increases step by step, indicating a test where varying flow rates are applied. This is characteristic of an Interference test (Q), which is used to measure the pressure response at observation wells when different active wells are producing at different flow rates. Therefore, Q corresponds to Profile (II). - Profile (III): The plot shows a pressure response that exhibits a clear curve after the initial change, indicating a Modified Isochronal test (S). This test method involves varying the well flow rate at specific intervals and observing the pressure change to determine well productivity. So, S corresponds to Profile (III). - Profile (IV): The pressure declines over time with some fluctuations, which is typical of the Flow-after-flow test (P). The graph indicates production over time, with small changes in pressure reflecting the conditions during the production test. Therefore, P corresponds to Profile (IV). Thus, the correct match is: - P – II: Flow-after-flow test - Q – III: Interference test - R – I: Fall-off test - S – IV: Modified isochronal test Final Answer: P – II, Q – III, R – I, S – IV