816 Subsurface Geologic Methods 



number of stands of recovered fluid should be listed. From the volume and 

 type of fluid recovered and the time duration of the test, the rate of flow 

 into the pipe can then be calculated. All fluids and gases should be sampled 

 and described. 



When depth and other drilling conditions make it practical, de- 

 pending upon the nature of the formation encountered, formation tests in 

 wildcat wells should be made on the upper five to ten (or less) feet of any 

 permeable interval where production possibilities appear favorable. When 

 a productive interval is encountered, subsequent tests should be made on 

 overlapping intervals to locate gas-oil and oil-water contacts. On wells 

 subsequent to the first on a structure, intervals to be tested can be more 

 closely planned from results of the first well. Provision must be made to 

 record volumetric measurement of all oil, gas, or water recovered. 



In exploratory work the well-site geologist jnay be responsible for 

 recording formation-test data. A recording form commonly followed is 

 given below: 



Formation Test No. 12 of Interval 8,028'-8,183' on June 15 and 16, 1945: 

 On June 15th set Olympic packer at 7,948' on 23/8" tubing. Tail to 7,999', 

 %"" choke in packer. Before setting packer, displaced 5,670 lineal feet of mud 

 in tubing with 160 cu. ft. of water. After setting, tested packer ; OK under 2,000 

 psi. Started swabbing operations at 1:00 a.m. on the 15th. At 8:00 a.m., top 

 of fluid at 5,790' — swabbed from 6,600'; swabbed fluid consisted of mud; tools 

 indicated fluid level between 7,400' and 7,700' while swabbing from 7,904'. 

 Tliis may have been the top of the mud column with tools showing no pick-up in 

 an overlying aereated column of commingled oil and gas. After gas reached 

 surface, fluid showed an increasing percentage of oil as swabbing operations con- 

 tinued. Swabbing continued until 6:30 p.m. on the 15th — fluid level approx 

 imately 7,000' with fluid essentially free oil and emulsion; no free water. Up 

 to this time, well made no flow heads. Shut well in at 6:30 p.m. (15th). Well 

 remained shut in from 6:30 p.m. to 12:30 p.m. with shut-in surface pressures 

 as follows: 



7:30 p.m. — 575 psi 

 8:30 p.m.— 825 psi 

 9:30 p.m.— 1,125 psi 

 10:30 p.m.— 1,350 psi 

 11:30 p.m.— 1,500 psi 

 12:30 a.m.— 1,650 psi 

 Opened well at 12:30 a.m. through a 8/64" bean. After releasing pres- 

 sure, flow was continuous — fluid oil with some emulsion. No free water 

 After equilibrium flow conditions had been established, tubing-head flow pres- 

 sure approximated 225 psi. 



During a two-hour gauge ending at 12:45 p.m. (16th) production totaled 

 8.61 bbls. (4.3 B/H or 103.2 B/D) through a 8/64" bean. Total cut 3.8%— 

 water testing 192 G/G salt. Without changing the bean setting, measured gas 

 rates between 1:20 and 2:25 PH as follows: 



Time 24-hour rate Time 24-hour rate 



1:20 p. m. 360 Mcf 1:55 p. m. 330 Mcf 



1:25 p. m. 350 Mcf 2:00 p. m. 348 Mcf 



1:30 p. m. 348 Mcf 2:05 p. m. 340 Mcf 



1:35 p. m. 352 Mcf 2:10 p. m. 314 Mcf 



