From 2f18b68f38192f3db01f64e34f74ac584024a0be Mon Sep 17 00:00:00 2001
From: Kai Bao <kai.bao@sintef.no>
Date: Mon, 17 Nov 2025 12:45:54 +0100
Subject: [PATCH] not creating identity matrix for singular matrix inversion

in StandardWellEquations.
---
 opm/simulators/wells/StandardWellEquations.cpp | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/opm/simulators/wells/StandardWellEquations.cpp b/opm/simulators/wells/StandardWellEquations.cpp
index 5231342ebf..6649c84f13 100644
--- a/opm/simulators/wells/StandardWellEquations.cpp
+++ b/opm/simulators/wells/StandardWellEquations.cpp
@@ -159,16 +159,8 @@ void StandardWellEquations<Scalar, IndexTraits, numEq>::apply(BVector& r) const
 template<typename Scalar, typename IndexTraits, int numEq>
 void StandardWellEquations<Scalar, IndexTraits, numEq>::invert()
 {
-    try {
-        invDuneD_ = duneD_; // Not strictly need if not cpr with well contributions is used
-        detail::invertMatrix(invDuneD_[0][0]);
-    } catch (NumericalProblem&) {
-        // for singular matrices, use identity as the inverse
-        invDuneD_[0][0] = 0.0;
-        for (std::size_t i = 0; i < invDuneD_[0][0].rows(); ++i) {
-            invDuneD_[0][0][i][i] = 1.0;
-        }
-    }
+    invDuneD_ = duneD_; // Not strictly need if not cpr with well contributions is used
+    detail::invertMatrix(invDuneD_[0][0]);
 }
 
 template<typename Scalar, typename IndexTraits, int numEq>