You continue not using static references to the columns as:

> ibDsqlEcon3v.parambyname('cartao').asInteger :=

tbEconv3.fieldbyname('cartao').asInteger;

You could to do:
var tbcartao:tib_column;

....
...
if not ibDsqlEcon3v.Prepared then
ibDsqlEcon3v.Prepare;
tbcartao:=ibDsqlEcon3v.parambyname('cartao');
....
While not tbEconv3.Eof do begin
tbcartao.asInteger := tbEconv3.fieldbyname('cartao').asInteger;
/*if you can use also static references to
tbEconv3.fieldbyname('cartao')*/
....
ibDsqlEcon3v.ExecSQL;
...
...
end;
...
...


Luiz.