<?xml version='1.0' encoding='utf-8'?>
  <soapenv:Envelope xmlns:soapenv="http://www.w3.org/2003/05/soapenvelope">
    <soapenv:Body>
      <ns:initializeResponse xmlns:ns="http://context.ws.blackboard">
         <ns:return>0066012c76be4260b4b3f466b20e8be0</ns:return>
      </ns:initializeResponse>
    </soapenv:Body>
</soapenv:Envelope>

Been trying this:

resp_extract    xmltype;

resp_extract := resp.extract('/soapenv:Envelope/soapenv:Body/child::node()', 'xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope"');