xml[0] = "<cards><c num='0000000001' /><c num='0000000005' />...</cards>" 
xml[1] = "<cards><c num='0000000086' /><c num='0000000147' />...</cards>" 
xml[n] = "<cards><c num='00000xxxxx' /><c num='00000sssss' />...</cards>" 

                select i.*
                  from XXX.CARD_INFO i,
                       (select to_number(extractValue(COLUMN_VALUE,'C/@NUM'))  CARD_NUM
                           from table(xmlsequence(xmltype(:cardsXML).extract('//C')))
                        ) p 
                 where i.CARD_NUM =  p.CARD_NUM

            // Первая порция            
            c.Parameters.Add("cardsXML", OracleDbType.VarChar, 4000).Value = cardsXMLs[0];
            var result = c.FillToNewDataTable();
            // Остальные если нужно
            for (int i = 1; i < cardsXMLs.Count; i++)
            {
               c.Parameters["cardsXML"].Value = cardsXMLs[i];
               result.Load(c.ExecuteReader());
            }

 select i.*
                  from XXX.CARD_INFO i,
                       (select to_number(extractValue(COLUMN_VALUE,'C/@NUM'))  CARD_NUM
                           from table(xmlsequence(:cardsXML.extract('//C')))
                        ) p 
                 where i.CARD_NUM =  p.CARD_NUM

c.Parameters.Add("cardsXML", OracleDbType.Xml).Value = new OracleXml(xmlText);

                select i.*
                  from XXX.CARD_INFO i,
                       (select to_number(extractValue(COLUMN_VALUE,'C/@NUM'))  CARD_NUM
                           from table(xmlsequence(xmltype(:cardsXML).extract('//C')))
                        ) p 
                 where i.CARD_NUM =  p.CARD_NUM

create or replace type NumberTable is table of number;

create or replace type NumberTable is table of number;

CREATE OR REPLACE TYPE SYS.ODCINumberList AS VARRAY(32767) of NUMBER
/

select to_number(COLUMN_VALUE)  CARD_PP_NUM  from table(cast(:cardList as SYS.ODCINumberList))

           
...IEnumerable<decimal> cardPpNums..
...

 var p = c.Parameters.Add("cardList", OracleDbType.Table);
            p.ObjectTypeName = "SYS.ODCINumberList";
            p.Value = cardPpNums;

select to_number(COLUMN_VALUE)  CARD_PP_NUM  from table(cast(:cardList as SYS.ODCINumberList))