Is the word estivemos the same in Brazilian and European Portuguese?

No.

While the spelling, meaning, and grammatical conjugation of "estivemos" are identical in both dialects, there is a difference in typical usage regarding the construction that follows the verb. In Brazilian Portuguese, "estivemos" is typically paired with the gerund (e.g., estivemos trabalhando). In Continental Portuguese, it is typically paired with the preposition "a" and the infinitive (e.g., estivemos a trabalhar). Additionally, there is a difference in pronunciation, as European Portuguese involves more significant vowel reduction and a different sibilant "s" sound.

Brazilian Portuguese

1. Nós estivemos trabalhando muito ontem. (We were working a lot yesterday.)
2. Nós estivemos comendo pizza no jantar. (We were eating pizza at dinner.)
3. Nós estivemos estudando para a prova. (We were studying for the exam.)
4. Nós estivemos esperando o ônibus por uma hora. (We were waiting for the bus for an hour.)
5. Nós estivemos assistindo ao filme. (We were watching the movie.)

Continental Portuguese

1. Nós estivemos a trabalhar muito ontem. (We were working a lot yesterday.)
2. Nós estivemos a comer pizza no jantar. (We were eating pizza at dinner.)
3. Nós estivemos a estudar para o exame. (We were studying for the exam.)
4. Nós estivemos à espera do autocarro por uma hora. (We were waiting for the bus for an hour.)
5. Nós estivemos a ver o filme. (We were watching the movie.)