The Research Of Water Injection Method To Improve Development Effect Of Sa-Ⅰ Group In Lamadian Oil-field

The vast majority of oilfields In China have applied water injection development method, especially since 1973 Lamadian Oilfield simultaneously applied water injection and well putting into production to ensure the development effects effectively in the early epoch of oilfield development, oil output in Lamadian Oilfield have reached a maximum of 1350×104t, which plays a larger role to ease energy tension.However, with the gradual deepening of oilfield development, contradictions of oil layers become increasingly prominent. particularly, after improving the method of the injection-production ratio and water injection pressure continuously, though it greatly improves the development effect of the low water cut production and thin oil layer, it also lead to increasingly conspicuous contradiction of large pressure difference between oil reservoirs.At present, the film sets of the composition loss of Savimbi one group has become a important issues to oil Lamadian's persistent stable production, until September 2007, Casing damage of Lamadian Oilfield Group Savimbi zero group~ Savimbi 4 section have reached a total of 226 wells, accounting for 29.2% of the total number of the over years loss wells in Lamadian oilfield .In order to prevent and control the casing damage effectively, nearly 70% of the injection wells have taken measures of stop and control injection, caused a result that the reservoir recovery of Savimbi one group is only 32.6%. Therefore, launch a study reasonable injection water methods in Savimbi one group based on the prevention of casing damage, has much favor of solve various types of reasonable oil injection-production ratio and the determine of the reasonable technology boundaries of the rational pressure injection-production, so as to further enhance Savimbi one Group and the development of various types of reservoir effect, and provide efficient experience and technical support for the oilfield persistent stable production.Through the study of the effective water injection method in the north group Savimbi of Lamadian oil fields, main results achieved as follows:1,Savimbi one-group develops a small number of underwater channel sand body in each sedimentary unit, especially underwater channel sand body which the SaⅠ3,4,5 sedimentary units developed are much more, and connectivity is better than in SaⅠ1,2 sedimentary units .2,Studies of Savimbi one-group reservoir sensitivity have shown that Savimbi reservoir is weak-speed sensitive, strong water-sensitive ~highly water-sensitive reservoir,strong acid sensitivity ~ strong alkali sensitivity.3,From the changes in the relationship between formation pressure and oil recovery that determined the reasonable pressure group of Savimbi one group as 10.7MPa; and from the casing damage, fault rupture compound, as well as the perspective of oil have been the biggest reasonable water injection pressure as 12.8MPa. The relationship between formation pressure and flow pressure a reasonable limit of pressure and flow as 5.2 MPa.4,When the optimal injection-production balance is achieved,the injection intensity in wells is not changed, layer pressure maintains at 10.7MPa, while the liquid production per unit thickness of oil well is 4.1m3/(d﹒m), which is 1.7m3/(d﹒m) Improvement more than the current oil production intensity.5,Savimbi one group to resume water injection pressure should be controlled in the following 12.5MPa, the effective thickness of water equivalent strength shall be controlled at 5.0m3 / d·m.6,Savimbi one-group reservoir can restore water injection moderately, but we must strictly control the water pressure and water intensity within5.0m3/d?m.7,Moderate water injection in pilot area of La 11-163 Savimbi one group have shown that the strict control of water injection pressure and injection intensity can effectively control the casing damage and improve the development effect of Savimbi one group...