Interwell Connectivity Study In The AD4 Well Area Of ??Tahe Fracture-cavity Reservoir

Tahe oil field is kind of complicated carbonate oil reservoir, characterized by its strong heterogeneity and complex oil-water relationship. It is formed by a long period of tectogenesis and ancient karst, which is mainly controlled by karst fracture-cave pools. As one of the largest area of Tahe oil field, Tahe 12 district diplays multiple fracture-cave and pressure system, extremely complicated interwell connectivity and various well production performance. Now, energy depletion has become the main factor affecting the field development, and an increasing number of wells treated with the water-flooding huff and puff has entered the low effectivity or failure stage, making the expansion of unit water flooding the first priority. Therefore, as the foundation of unit water flooding, the interwell connectivity study is of greate importance. In this paper, based on the geological and production data, the inter well connectivity of AD4 well unit has been obtaind with a combination method of static modeling and dynamic analysis. Finally, by studying the influence factor of water flooding under different interwell connectivity situation, optimal waterflooding method has been proposed.First, according to the seimic data and logging data, the geological model is established by means of deterministic modeling. Based on the geological model, the suface weathering crust and deep fractures are proved to be the main connectivity form of AD4 well unit.Second, based on the dynamic well production data, the water flooding curve and material balance methods are used to evaluate the single well dynamic reserves and the reservoir characteristics. Then by analysing the production interference and the injection-production relationship, the dynamic interwell connectivity of AD4 is recognised.Third, according to the prinple that the static analysis should surrender to the dynamic one, while the dynamic analysis must be based on the static one, the interwell connectivity situation is enventually obtained after a thorough comparison between the static and dynamic conclusion.Finnally, based on the interwell connectivity study result, the mechanism model is founded for three kinds of connection form, that is fracture-cave, cave-fracture-cave and fracture-cave-fracture. Research is conducted on the influence factors of water flooding performance under differen connection forms, and the according optimal waterflooding methods have been proposed.