Why is the weight of both water and natural gas as substances so important when speaking about the understanding of principles of gas-lift?

18. When the natural gas enters the liquid in the tubing, the gas makes this liquid column much lighter in weight.

What factor causes the decrease of weight of the liquid column in the tubing?

19. Since the liquid column is lighter, it exerts less pressure on the bottom of the well.

What changes on the bottom of the well take place when the liquid column becomes lighter?

20. With the pressure lower at the bottom, the pressure remaining in the reservoir becomes sufficient to push reservoir fluids to the surface through the tubing.

What processes at the bottom of the well are observed on condition of the lower pressure there?

21. Gas may be injected continuously or intermittently, depending on the producing characteristics of the well and the arrangement of the gas-lift equipment.

What factors determine and provide the process of the continuous or intermittent gas injection?

22. Gas lift is common when a supply of gas is economical and available and when the amount of petroleum it will lift justifies the expense. Gas lift is especially suitable for offshore use because platform space is limited and gas-lift equipment is largely downhole.

What factors make gas-lift be considered the most suitable for offshore use?

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Production Tests

23. Production tests help determine how much and how fast a well will produce.

What reason can be considered the most important while undertaking the production test?

24. The company representative may run production tests before or after setting casing, cementing, and perforating. Each test reveals certain information about a particular well and its reservoir.

What type of information do the production tests provide and when do these tests are done?

25. Accuracy is, of course, very important, and the data from these tests form the case history of a well.

Where are the accurate data obtained from the production tests used?

Potential Test

26. One of the most frequently performed production tests after completion is the potential test. A potential test measures the largest amount of gas and oil well can produce over a 24-hour period under certain fixed conditions.

What kind of well tests is the potential test and what is the main aim of its performance?

27. Basically, the test involves allowing the well to produce for a given period of time and accurately measuring the production.

What are the basic principles of the well potential test?

28. Lease operators perform potential tests both when first producing the well and again several times during its life.

How many times can the well production test be rationally performed as a rule?

29. State regulatory agencies usually require potential test information to establish the allowable production for the well.

For what purpose do state regulatory agencies usually require potential test?

Bottomhole Pressure Test

30. A bottomhole pressure test uses a gauge to measure the pressure at or near the bottom of the well.

By means of what appliance is a bottomhole pressure test measured?

31. The test is usually conducted after the well has been shut in for 24 to 48 hours.

When is the proper time for conduction of the bottomhole test?

32. When an operator schedules this test at certain intervals, it reveals valuable information about the decline or depletion of the zone in which the well is producing.

What kind of information does the operator reveal while scheduling the test at certain intervals?

33. For example, pressure measurements can tell the company representative the most efficient rate of flow for the well.

What kind of valuable information can the company representative obtain on the basis of the pressure measurements?

Productivity Test

34. A productivity test is a combination of a potential test and a bottomhole pressure test. It determines the effects of different flow rates on the pressure in the well.

What kind of test is a productivity test and what essential process it determines?

35. This helps the company representative decide the rate at which the well should be produced for the best results.

What type of valuable data helps the company representative determine the rates of well productivity for the best results?

36. Producing at the maximum flow rate may deplete the drive too quickly or damage the well.

How large volumes of oil production may deplete the drive too quickly or damage the well?

37. The procedure for the test is first to measure the closed-in bottomhole pressure of the well and then to measure the flowing bottomhole pressure at several stabilized rates of flow.

What are two main steps in the procedure for the test which are considered to be rather important?

38. This type of testing is done on both oil and gas wells and is the most widely accepted method of determining the capacity of gas wells.

What type of test is considered to be the most widely accepted method of determining