Process for increasing the permeability of oil bearing chalk formations

Claim 1

A PROCESS FOR INCREASING THE PERMEABILITY OF OILBEARING CHALK FORMATIONS CONTAINING AS MUCH AS 10% HYDRATABLE CLAYS BY INHIBITING CLAY SWELLING DURING ACIDIZING WHICH COMPRISES INTRODUCING INTO THE CHALK FORMATION A CLEAR WELL-TREATING SOLUTION COMPRISING AN ACIDIZING AMOUNT OF HYDROCHLORIC ACID, AN AMOUNT OF ACETIC ACID SUBSTANTIALLY EQUAL TO THE AMOUNT OF HYDROCHLORIC ACID AND A SMALL AMOUNT OF THE FINAL REACTION PRODUCT OBTAINED BY CONDENSING ONE MOL OF A POLYETHYLENEAMINE SELECTED FROM THE GROUP CONSISTING OF DIETHYLENE TRIAMINE, TRIETHYLENE TETRAMINE AND TETRAETHYLENE PENTAMINE WITH AN EQUIMOLAR AMOUNT OF OLEIC ACID, REMOVING SUFFICIENT WATER FROM THE REACTION ZONE TO FORM AN INTERMEDIATE IMIDAZOLINE REACTION PRODUCT, REACTING THE INTERMEDIATE IMIDAZOLINE PRODUCT OBTAINED WITH AN EQUIMOLAR QUANTITY OF ETHYLENE OXIDE BY PASSING ETHYLENE OXIDE THROUGH AN ALCOHOL SOLUTION OF THE INTERMEDIATE IMIDAZOLINE PRODUCT AND RECOVERING A FINAL REACTION PRODUCT.