API RP 19B Section 2 Perforation Tests Conducted at Multiple Facilities to Guide the Latest Section 2 Revision

Abstract

Abstract The results of API RP 19B Section 2 tests conducted at eight charge manufacturer's testing facilities were used to determine whether differences in vessel size and configuration resulted in different depth-of-penetration results. Findings from these round-robin tests were also used to help guide changes to the newly revised Section 2 documentrecently voted on, approved, and currently in review by API. After agreement among the eight companies was reached on the testing specifics, the tests were conducted over a period of time, enabling an independent operator to observe the tests at each facility. A batch of quality, deep-penetrating shaped charge was supplied by a single manufacturer, and the rock targets were sourced from the same block to minimize differences and allow for fair evaluation of the different testing systems. The hardware materials and test configurations used in the tests were specified (scallop plate and casing coupon, wellbore and target pore pressures), and the independent operator verified that each test was conducted accordingly. The independent operator tabulated the penetration-depth and casing-hole-size data from the tests for comparison per Section 2 testing specifications. At each testing site, a set of successfully performed tests was conducted at confining stresses of 1,500, 3,500, 6,500, and 9,500 psi. The resulting penetration depths were all plotted versus confining stress on the same chart. A statistically significant correlation was found between penetration depth and confining stress (as expected); with a minor correlation with porosity. Most of the scatter in the data was observed at confining stresses of 1,500 and 3,500 psi. A statistical analysis showed that the diameter of the core (4, 5.25, and 7 in.) did not influence the penetration results for this particular deep-penetrating, 21-g explosive shaped charge. This knowledge enables a testing company to conduct Section 2 tests at a lower cost. Additionally, based on statistical analysis, the option of housing the shaped charge within the wellbore chamber versus an open-style configuration is valid because it did not affect the penetration results. The information and results collected from the eight different facilities provide options for vessel type and system configuration and also suggestthe variance to expect in Section 2 tests. Insight into the methods used for conducting these tests and background information on handling the cores are included.