The Detailed Study And Predict Evaluation About The Lower Triassic Reservoir In Heba Region, Northeast Of Sichuan Basin

He ba structure which is one of structures in Tongnanba tectonic of Northeast Sichuan, is an important natural gas exploration and development region. From finishing drilling wells, such as Heba-1, Heba-2, Heba-1, Heba-102, Heba-101 and so on, it has drilled favorable formation and obtained industrial high productivity capacity in Feixianguan and Jialingjiang Formation of lower Triassic. Thus it reveals that the natural gas exploration and development will have a good prospect in lower Triassic of Heba tectonic. Therefore, it has a great significance that we carry out detailed reservoir studies and accurately grasp the distribution law of reservoir extensions and scientifically assess the low Triassic formation for next exploration and development in lower Triassic of research area.Based on the previous studies, this paper take full advantage of available data, involving geological data, well logging, seismic data and so on, to carry out detailed reservoir studies. The studies include the deposition pattern analysis of Feixianguan and Jialingjiang Formation in lower Triassic, study of stratigraphical features and sequence stratigraphy, study of seismic response characteristics of beaches and beach's score , study of reservoir characteristics and reservoir's control factor and study of prediction and evaluation of reservoir.Through the study, We can realize that: (1)the sedimentary framework of the Feixianguan Foramation inherit the characteristics of Changxin Formation which is mainly filling and leveling. After later Feixianguan 3 member, this paleogeographic f??work is nearly filling and leveling, then the region of interest evolve to platform. (2) The Feixianguan Formation is divided into 2 3rd-order sequences in the region of interest, and each sequence includes LST, TST, and HST. The Jialingjiang Formation is also divided into 2 3rd-order sequences, but both two sequences only include TST and HST. (3)The main reservoirs are arene beach of the second member of Jialingjiang Formation and oolitic beach of the third member of Feixianguan Formation in the lower Triassic of the region of interest. We obtain the seismic response feature of beach body from seismic data, the beach's seismic reflection wave in seismic cross section display branch off, annexation and overriding. The featuer of beach bottom in seismic cross section is continuous strong seismic wave crest, and the feature of beach ridge in seismic cross section is feeble amplitude feeble continuous and aberrant wave crest, and seismic wave of beach body display concave down in the external form. (4)Observing from core and core wafer, we recognize that the main reservoir rock is oosparite and dolarenite, and the main reservoir pore space is intragranular emposieu and moldic pore, and the secondly reservoir pore space is intergranular pore. (5)The main diagenesis have compaction, pressolution, cementation, denudation, dolomitization, rejuvenation of crystals, and cataclasis,and so on, and the denudation and dolomitization play dominant role on the reservoir pore forming. (6)The reservoir forming is controled by depositional palaeogeographic environment, diagenesis and tectogenesis. (7) The Heba 102 well field, Heba 2-Heba 1 well field, Heba 101 well field and the north of Heba 101 well field, and the southern region of interest are the regions where the beach body is more development.