Aug 7 (Reuters) - Nuvista Energy Ltd NVA.TO :
* ANNOUNCES SECOND QUARTER 2018 FINANCIAL AND OPERATING RESULTS
* QTRLY PRODUCTION OF 36,035 BOE/D, UP 42 PCT
* QTRLY ADJUSTED FUNDS FLOW $0.40/SHARE
* UPDATED ANNUAL PRODUCTION GUIDANCE FOR 2018 TIGHTENED TO 36,000 BOE/D-38,000 BOE/D
* ADJUSTED FUNDS FLOW GUIDANCE FOR 2018 INCREASED TO $240 MILLION - $260 MILLION