| Zhongguai uplift closed to the Mahu,Shawan and PEN1 well west hydrocarbon depressions is an inherited palaeo-uplift.The Zhongguai uplift is also an inherited convergence belt of oil and gas and has many hydrocarbon layer systems.The Jiamuhe formation which at the edge of the Zhongguai uplift is close to the source rocks,has large-scale truncated-overlapped structural belt,nice source-reservoir-caprock combination and the relative high quality reservoir,and can formed the stratigraphic hydrocarbon reservoirs.Many wells have found the oil and gas proof these areas are the favorable areas of oil and gas exploration.In the last two years,the oil and gas exploration from the volcanic reservoirs in the Jiamuhe formation nearby the JL2 well has many important discoveries.Compared to the volcanic reservoirs,the glutenite reservoirs in the Jiamuhe formation at the south slope are thicker,larger,and have the better exploration potential.At present,the XING1 well and G3 well have found the commercial valuetested gas pools,G201 well has found the low-duty gas pools.Those elements illustrate that the next large-scale gas reservoir mostly can be found from the glutenite reservoirs.But many factors block the exploration progress in this area,include the Jiamuhe formation is deep(>4500m),the production is low and decrease fast,the production always has water,the types,control factors and reserves' sizes of gas reservoirs are all unclear,and so on.To solve these problems,sequence strata has been divided and compared,regional structure has been interpreted and diagrammed,palaeo-geomorphology and sedimentary facies have been analyzed,reservoir has been evaluated and the main control factors have been analyzed,old wells have been reviewed,reservoirs have been dissected fine,and comprehensive analysis of engineering geology have been done.Research results show that,(1)the 4 salients and 3 depressions nearby the Zhongguai uplift controlled the distribution of Jiamuhe formation.The thick glutenite what developed in the second sand set of the second member in Jiamuhe formation mainly distributed in the three sub-sags.(2)The glutenite in the second member of Jiamuhe formation is the delta facies sediments.The sedimentary facies controlled the reservoir properties by controlled the content of laumontite.The front-delta which the content of the laumontite is 8%?12%is the developed zone of the relative high quality reservoir.(3)The three wells what produced the gas in Jiamuhe formation in XING 1 well field are belonged to the same gas pool.This gas pool is a stratigrapgic-lithologic hydrocarbon reservoir,and it is formed under the background of the stratigraphic pinchout upward tilt direction.The thick mudstone of Wuerhe formation formed its roof,the tight glutenite of Jiamuhe formation formed its floor,and lithologic pinchout on wings and downdip direction.The reservoir porosity is about 8%and permeability is between 0.001?0.5 m D,that referred to as extremely low porosity and permeability glutenite.The gas reservoir contains original residual occlusion water,and the water energy is limited and inactive.The early reservoir reconstruction fails to reach the due effect,the potential of increasing production of horizontal well is huge,and has the development value.These researches have confirmed the distribution range of glutenite exploration favorable areas around Zhongguai uplift,and the exploration situation has been strengthened further.The exploration disposition in the favorable areas of Jiamuhe formation around Zhongguai uplift step by step,will realize the glutenite entire exploration succeeds.At the same time,it is an important reference to the glutenite exploration of Jiamuhe formation,Fengcheng formation and Xiazijie formation in northwestern edge of Junggar Basin. |
PDF Full Text Request