Study On The Interpretation And Evaluation Methods Of The Water-flooded Layer In The Tarim Clastic Reservoir

The clastic reservoirs in the Tarim Oilfield have been water-injected for many years.The water content in the formation has increased and the flooding phenomenon has been serious.This has caused difficulties in the secondary interpretation and evaluation of the oil fields.This study combines the data of test oil production,production dynamics,etc.,and comprehensively analyzes the water-flooded layers of the target section of the reservoir.By comparing the differences before and after reservoir flooding,the logging response characteristics of the flooded layer in terms of natural gamma,natural potential,resistivity change,and neutron lifetime are summarized to qualitatively identify the flooded layer.At the same time,the original oil saturation calculation model,the irreducible water saturation calculation model,the residual oil saturation calculation model,the oil-water relative permeability calculation model,and the moisture content calculation model are established,and each parameter is reevaluated.For the recognition of flooded layer fluids,in addition to the conventional relative resistivity identification method,neutron life identification method,intersection plate identification method,and comprehensive analysis method,special identification methods for water flooded layers in different oil fields are established based on array induction.Water-flooded layer identification based on array induction(Lunan Oilfield),the original saturation inversion based on the reservoir characteristics(Donghetang Oilfield),and the time-reversal resistivity log-in comparison log(Hadexun Oilfield).Combined with the characteristics of different oilfields,the flooded zone is divided into four levels according to parameters such as oil saturation,water content,and flooding efficiency: non-flooded zone,weak(low)flooded zone,intermediate flooded zone,and strong(high)flooded layer.The comprehensive interpretation of well logging data from over 30 wells in the Tazhong 4 oilfield,the Lunnan oilfield,and the Donghetang oilfield has been performed,and the coincidence rate has reached over 85%.It is a well logging for the flooded layer of the Tarim clastic reservoir lay the foundation for interpretation and evaluation.