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

No.

While the core meaning and spelling of "encontrar" are identical in both dialects, the answer is no because there are fundamental differences in grammar (specifically clitic placement) and pronunciation. In Brazilian Portuguese, it is natural and standard to use proclisis, placing the reflexive or object pronoun before the verb (e.g., "se encontra"). In Continental Portuguese, enclisis—placing the pronoun after the verb (e.g., "encontra-se")—is the standard grammatical structure. Additionally, the pronunciation of the vowels in the word and its surrounding context is much more "open" and syllabic in Brazil, whereas it is much more "closed" and reduced in Portugal.

Brazilian Portuguese Examples

1. Eu encontrei meu celular na mesa. (I found my cell phone on the table.)
2. A gente se encontra no parque mais tarde. (We'll meet at the park later.)
3. Você não consegue encontrar o seu estojo? (Can't you find your pencil case?)
4. Eu me encontrei com ele no shopping. (I met up with him at the mall.)
5. Eles se encontram em uma situação difícil. (They find themselves in a difficult situation.)

European Portuguese Examples

1. Encontrei o meu telemóvel na mesa. (I found my mobile phone on the table.)
2. Encontramo-nos no parque mais tarde. (We'll meet at the park later.)
3. Não consegues encontrar o teu estojo? (Can't you find your pencil case?)
4. Encontrei-o no centro comercial. (I met him at the shopping center.)
5. Encontram-se numa situação difícil. (They find themselves in a difficult situation.)