A. Force my vector layer in openlayers to be 3D. with z value of 0.
B. use some (unknown to me) openlayers function to return a 3D version of the geometry (or WKT) given a 2D, with Z set to 0.
C. use Oracle (in my helper function) to make the sdo_geometry 3D (a different constuctor maybe?) currently using sdo_geometry(wkt_in,srid) srid is 8307 if that matters.
E. something else I haven't thought of :)