Summary

G.R. No. 238846 (SHELL PHILIPPINES EXPLORATION B.V. and CHEVRON MALAMPAYA LLC, Petitioners, v. COMMISSION ON AUDIT, Respondent);
G.R. No. 238852 (PNOC EXPLORATION CORPORATION, Petitioner, v. COMMISSION ON AUDIT, Respondent);
G.R. No. 238862 (THELMA M. CERDENA and NORA A. TUAZON, Petitioners, v. COMMISSION ON AUDIT, Respondent).

The crux of the controversy is Section 6.3 of the Service Contract No. 38 (Service Contract) executed on December 11, 1990 between the Government of the Republic of the Philippines, represented by then President Corazon C. Aquino, and contractors Occidental Philippines, Inc. and Shell Exploration B.V., predecessors-in-interest of petitioners Shell Exploration B.V. (SPEX), Philippine National Oil Company Exploration Corporation (PNOC-EC), and Chevron Malampaya LLC (Chevron).