Research On Reservoir Space And Development Dynamic Of Ordovician Reservoir In Tuofutai Area

Tuofutai area located in Shaya County and Kuqa County, Xinjiang UygurAutonomous Region. Structural position is located In the Southwest of Akekule shaft,Shaya tectonic uplift of the Tarim Basin. Previous studies of reservoirs in TaheOilfield is more concentrated in the main area.Reservoir studies in Tuofutai region isrelatively weak. Reservoir is buried deep, thin, strong heterogeneity, controllingfactor complex, resulting in favorable exploration target prediction difficult. Thereservoir space types of Tuofutai District have large differences with Tahe subject area.Reservoir connectivity is poor. Some wells sudden Minting in the higher yield.Therefore, this paper analyzed spatial distribution of reservoir and reason&countermeasures of production dips in the study area through a comprehensiveanalysis of test geophysical, logging, well testing and development dynamic data.Now obtained the following knowledge.（1）The factors of high natural gamma in top of Yijianfang is muddy, organicmatter or both of the two. The muddy sections generally do not develop reservoirs,then the organic matter sections may develop reservoir.（2）Horizontal fractures and bedding planes of the study area have obviousdifferences in the granularity&color of both sides of the core particle surface, fillingand width. Well sections main reservoir space types include cave type, high anglefracture type, low angle fracture type and seam holes are not developed type.（3）Dynamic development in the study area is broadly divided into threecategories: I class of wells, stable and high yield, stable pressure, II class of wells,stable or regular slow decline and high yield, the pressure drops rapidly, generallystable production after pumping machine, III class of wells, production decreasedrapidly or intermittent production, pressure drop quickly, very short flowing life.Corresponding to a reservoir space, I, Large fractured vuggy unit with active bottom water. II, Closed type small or medium-sized cave, III, small cave with high degreeof filling.（4）The study area as a whole is more fractured and cave development, andmore development of small and less connectivity cave. Well, along TP246X andTK1024line high degree of corrosion. reservoir space is better developed than otherlocations and develop large joints strong connectivity Cave unit. Longitudinaldevelopmental case is the closer to the top of Yijianfang the better. Most reservoir space developin the top of Yijianfang within a range of60meters.（5）The reason of production dips in study area can be divided into three types:1, Most of the production dips due to the change of pressure gradient caused by crudeoil degassing,2, Some production dips is because of the change of reservoir properties,3, A few wells minting due to the increase rate of water in the production process.The corresponding countermeasures:1, Water injection for pressure,2, Acidfracturing for reservoir reconstruction,3, Reasonable control of the productionprocess.