assignment 59

Project Statement

G3P1 (Selected Topics)

Well Testing (Group 1)

You are a reservoir engineer in an oil company, and you are assigned to do several tasks in well testing analysis for two different wells by using two different well tests:

First week objective:

Task 1:

· Give an introduction about well testing main types and how they are conducted? With explanation.

· Explain in detail the following terms:

(a) Well bore storage effect.

(b) Line source solution.

(c) Cartizean (linear) analysis method.

(d) Semi-log analysis method.

(e) Log-log analysis method.

(f) Dietz shape factor.

Task 2:

· Derive the diffusivity equation and explain how it links to the well testing for oil reservoir analysis on the following condition:

(a) Steady state condition

(b) Pseudo state condition

(c) Unsteady state condition

Second week objective:

Task 3:

· What are the problems that might face you during well testing and how to check if the data are valid?

Take 4:

· What are the procedures, required equipment, and the assumed cost of the conducted buildup and drawdown tests?

Third week objective:

Task 5: Analyze these two given tests of well testing and define their types and determine its requirements.

Test 1: Analyzing Single-Rate, Single-Phase Pressure well test a constant-rate well test was run in an oil well with the following characteristics: = 250stb/day, = 0.8 cP, = 1.136 rb/stb, = 17.0 x , = 0.039, h = 69 ft, = 4412psi, and = 0.198 ft. Last flowing time = 460 hr. From the test data given in Table 1, plot the data and estimate the formation permeability, skin factor, pressure drop across skin, flow efficiency.

Table 1: Well test data (Single-Rate and Single-Phase Well test)

Test 2: A single-phase and single-rate pressure well test was conducted on an oil well. The data in the first two columns of Table 2 were recorded. The following well/reservoir parameters are given: = 1.224 rb/stb, h = 55 ft, = 0.06, = 0.21 ft, = 1.5 x, and = 0.65 cP, = 14.65 psia, T = 200, = 1520ft, and = 53.5/ . Assume the well is draining from the center of a square. Well depth = 4500 ft. = 13630 hours. Plot the data in table 2 and find the requirement below:

1. Formation permeability, K

2. Skin factor, S

3. Additional pressure drop near the wellbore, (

4. Effective wellbore radius,

5. Flow efficiency FE using p*

6. Damage ratio DR using p*

7. Productivity index, PI

8. Radius of investigation (determine the radius of investigation at = 6 hours and 50 hours).

Table 2: Well test data (Single-Phase Well test)

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