Last week I moved some Data Access Layer code from MSSQL to Oracle and I started out downloading the Oracle provider for .NET from OTN. I thought that OracleHelper would work well with the provider from Oracle, but it didn't. At least not the provider for Oracle 9.2.
So I went with the System.Data.OracleClient namespace instead and it works like a charm.
The OracleHelper that looks and works similar to the SqlHelper 2.0 class is available in the Nile 3.0 sample project from Microsoft.