String url = "http://localhost:11528/FlowEngine.asmx";

String soapAction = "http://tempuri.org/ProcessFlowRequest";

var soapClient = new SoapClient(url, soapAction);

soapClient.Arguments.Add(new SoapParameter("requestXml", "{'Head': { 'MethodCode': 'M1001', 'Security': { 'Token': ''}},'Body': { 'FlowID': 'ca0a9a91-bb13-4717-8590-d9258f5c292f'}}"));

Object ob = soapClient.GetResult();