Here and there migrate/upgrade projects for SoaSuite10g to SoaSuite11g are running. Most of the time the source is committed to Subversion. It turns out that JDeveloper makes a full copy of the project folder at upgrade.
This means that also the .svn folders are copied. And you probably don't want that. I would have the new project in a different branch in my subversion folder.

At a former customer there was a registry file that creates a menu item in the Windows explorer pop-up menu. This would hierarchically delete all .svn folders in the selected folder. But not allways you're able to install such a shell-command.

So I created a little ant script. Since we're working with JDeveloper11g, we have an Ant install. I also created a windows bat file to run the ant script with a folder that can be given as a command line parameter.

The build.xml:

<?xml version="1.0" encoding="windows-1252" ?>
<project default="run">
  <target name="run">
    <tstamp/>
    <property environment="env"/>
    <property name="scan.folder" value="${env.SCAN_FOLDER}" />
    <!--<property file="./build.properties"/>-->
    <echo message="Delete all .svn from ${scan.folder}"></echo>
    <delete includeemptydirs="true"  verbose="true">
      <fileset dir="${scan.folder}" includes="**/.svn/**,**/.svn" defaultexcludes="false"/>
    </delete>
  </target>
</project>

The fileset in the delete can be found as an example in the doc of the Ant Delete Task. However, I found that the example did not work as such, for .svn folders with content. So I expanded the includes property to "**/.svn/**,**/.svn" to delete the content of .svn folders, before deleting them.
I set the verbose attribute, to see which folders/files are actually deleted.

The delete deleteSVNFolders.bat file is:

@echo off
cls
set ORACLE_HOME=d:\oracle\Product\JDeveloper11116\Middleware
set ANT_HOME=%ORACLE_HOME%\jdeveloper\ant
set PATH=%ANT_HOME%\bin;%PATH%
set JAVA_HOME=%ORACLE_HOME%\jdk160_24
set SCAN_FOLDER=%1
ant

You'll have have to change the ORACLE_HOME setting to point to your JDeveloper middleware home.
Of course this works on linux as well, but than you'll have to transform the bat file to a bash script. But that's no rocket science...