ag.algebraic geometry – Accuracy of sequences preserved under singularity resolution

Leave $ X $ be a noetherian singularity, affine, normal, isolated and $ pi: widetilde {X} a X $ Be a resolution of singularities. Suppose we have an exact sequence (not necessarily short):
$$ mathcal {O} _X ^ {a_1} xrightarrow { phi_1} mathcal {O} _X ^ {a_2} xrightarrow { phi_2} mathcal {O} _X ^ {a_3} $$
with $ phi_1 $ Y $ phi_2 $ defined by a $ a_1 times a_2 $ Y $ a_2 times a_3 $-matrices respectively, with coefficients in $ Gamma ( mathcal {O} _X) $. Using natural inclusion $ Gamma ( mathcal {O} _X) subset Gamma ( mathcal {O} _ { widetilde {X}}) $, the matrices corresponding to $ phi_1 $ Y $ phi_2 $ define natural morphisms $ phi_1: mathcal {O} _ { widetilde {X}} ^ {a_1} to mathcal {O} _ { widetilde {X}} ^ {a_2} $ Y $ phi_2: mathcal {O} _ { widetilde {X}} {a_2} to mathcal {O} _ { widetilde {X}} ^ {a_3} $. It is the resulting complex
$$ mathcal {O} _ { widetilde {X}} ^ {a_1} xrightarrow { phi_1} mathcal {O} _ { widetilde {X}} ^ {a_2} xrightarrow { phi_2} mathcal {O} _ { widetilde {X}} ^ {a_3} $$ also accurate?