Technique Study To Improve Exploitation Effect In Long Dong "Double High" Jurassic Oil Field

Long Dong Jurassic oil field has come into a "double high" period of development (the degree of reserve recovery of oil initially in place is up to21.5%and the composite water percentage is83.6%) after forty years development. Because of long time of reservoir development, the shaft state is complex and many oil/water wells’ casing are damaged; the injection-production pattern is defective, so the effect of waterflooding is poor. The distribution of remaining oil is dispersive, which has made the stable production difficult. But there is a great quantity of remaining recoverable oil(1009×104t) in reservoir, and it needs to take many methods to research the distribution of remaining oil, then to determine potential area for stable yields, and to optimize the stable yields technical research in different period and reservoirs,to resolve the discrepancy and problem to restraint the old oil fields stable yields, so that to enhance the reservoir controllability and the degree of reserves pruduction, and then to improve the effect of the fields development.In this paper, the geologic characteristic, current status and feature of xploitation of the Jurassic reservoirs were analysed. And based on this,the characteristic of geologic and breakthrough rule were researched for the Jurassic "double high" reservoirs of Long Dong field. The former technology strategy to improve injection and producti-vity were evaluated, and then the development technique policy and the adaptability potential technology which are to control water and to steady oil production were made. The major work is to analyse the new oil/water wells for three blocks(the Middle1, North2and South2block) from2004to2006, to prove the validity of the reservoir numerical model over the years, to analyse and sum up the distribution of remaining oil and effect factors of Ma Ling oil field, and to figure out the distribution of space and plane about remaining oil, which could provide relatively reliable reference to adjust and administer the effect of block development and at last to enhance oil recovery.Based on different characteristics of reservoir and distribution of remaining oil of Jurassic reservoirs, the used stable yields method was analysed, and it is of great significance to exploit the reservoir potentialities, to raise the degree of reserves used and then to make the reservoir come to be stable yields in the high containing water period.