5-3 Production data for a well has been plot- 5 ted on semi-log paper. Careful analysis indicates k that the well is declining hyperbolically. Your best fit has a " of 0.5, qi of 80 BOPD and a Di of 0.65/year on August 1, 1982. Actual production between July 1, 1982 and 12-31-82 is 12,000 Bbl. a) What are the flow rate (BOPD), decline rate (I/year), and "b" on 1-1-83? Effective 1-1-83, how many barrels are remaining if the economic limit is 3 BOPD? b) c) What are Qi and Di on 7-1-82? Using the hyperbolic fit of the data, what would be the production between 7-1-82 and 12-31-82? d) What is the EUR for this well (Qel 3 BOPD)? e) Example 5-8 Hyperbolic Decline -Type Curve e production data, semilog plot, and log-log plot for a hyperbolic well (presented at the end of sis for decline curves. The type curve is included in the back pocket. Plot the data (pages 5-31 and 5-32) and verify the following Th this exampl) are designed to demonstrate the mechanics of type curve analy match points. Your plot should look like the log-log plot on page 5-30 Match Point No. 1 Match Point No. 2 t 10 mo. q(t) = 1000 Dd 0.42 Dd 0.33 q(t) 10,000 tDd = .042 Oil Property Evaluation Example 5-8 Continued) To solve for b, qj, and Di Place transparent log-log overlay on top of the type curve so that our match point values of gp and tpy on the type curve correspond with the match point values of q and t for the values of production. Although only one match is required, two match points have been given. This will insure that the horizontal and vertical axes of the log-log plot and type curve are parallel (maybe). 2. Once the match has been made, notice that the production on the log-log plot corresponds with the type curve having and art begins. You probably could find a match for other values of "b". This is true even with 4 years of production history. It is almost impossible to come up with a good match with less than 3 years of production history unless the initial decline rate is quite high value of 0.6. This is where the a plication of science ends 3. Now, calculate the values of q, and D a. For the first match point. 9Dd D.t Dd q)-10,000 BOPM Ds 3.3 tDd = 0.042 10.000 3030 BoPM 3.3 D, - 0012 - 0.042/mo. For the second match point. qt) 1000 BOPM Dd0.33 b. Dd0.42 1000 0.33 3030 BOPM 042 = 0.042/mo q 0.33 D10 Notice that both match points gave the same result. If the time t is increased by a factor of 10, dimensionless time 'Dg is also increased by a factor of 10, thus the value of D, is the same. The same concept is true for different values of q(t) and gp Thus, once a good "fit" is found for the log-log plot of the production data and one of the curves on the type curve, the match point can be taken anywhere on the plot that is convenient. 5-28
