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Based on the data of core, thin section, scanning electron microscopy and geochemical analysis.etc, from the dissolution phenomenon of laumontite in the carboniferous volcanic reservoirs of Santanghu Basin,the exploratory study of alkaline diagenesis and the formation mechanism in volcanic reservoir was carried out.

Through core observation and description, whole rock chemical analysis, thin section identification and logging identification method, The volcanic rock of this area is mainly basalt, trachyte and tuff, three major categories, further divided into 10 subclasses. Basalt intergranular-intersertal structure, the main minerals are plagioclase , sodium feldspar and mafic pyroxene , belong to alkaline series,infrasonic wave, low natural gamma, high resistance, high density; Trachyte ,typical rough structure, high content of feldspar, the negative anomaly of naturalelectric potential, high resistance, high natural gamma measurement, infrasonic wave;Tuff, tuffaceous texture, massive structure, rock is composed of lithic, vitric, crystal and volcanic ash, ingredients to alkali feldspar, biotite, plagioclase etc, low natural gamma, low resistivity , low density.

The research is carried out on diagenetic minerals, pore types and its impact on the physical properties in Huanjiang C81reservoir of Ordos basin, which is based on reservoir physical property test, thin sections observation and scanning electron microscopy. Several minerals closely associated with reservoir physical properties are identified from diagenetic effect views. It results in that a classification is proposed for the diagenetic facies, consisting of four kinds of diagenetic facies: ferroan calcite cementation facies, hydromica/kaolinite cementation facies, chlorite coating facies and feldspar dissolution facies. The study of C81reservoir in Huanjiang region shows that this scheme is favorable to estimate low permeability reservoir, the result shows fairly good consistency with the distribution of physical property of wells.

Gu 83 wellblock is the center of the Gulong reserves, the well test oil yield is high, the oil-bearing area shall, as reserves and production increase nine oil production company of Daqing oil field replacement area. On the basis of high resolution sequence stratigraphy theory, strata as the instruction, the trunk section and the well combination method is used to contrast layer and multiple well profile compared to small layer, establish high resolution stratigraphic framework. The Putaohua reservoir is divided into three sandstone under the group, which, subdivided three eight small layers for sandstone. Through well combine to determine the sequence division of the interface, divided into Putaohua reservoir. Considering lithology, curve characteristics of shaft vibration, even the well profile correlation research area according to the principle, method, sequence division division, in the Putaohua oil layer, three sets of sandstone under the group; On the segmentation, each group sandstone, upper sandstone will eventually set is divided into two layers of P11, P12; middle sandstone is divided into P13, P14, P15 three small layer; under sandstone under group is divided into P16, P17, P18 three small layer.

Fan delta facies deposition are developed in the steep slope of faulted lake basin and have features ,such as the rapid accumulation, from near provenance, clastic coarse granularity and poor sorting. By means of core, logging, well logging and seismic data, based on the sedimentary characteristics of Nantun formation of Wuerxun depression, the conclusions are as followings: Faulted basin steep slope belts are developed fan delta depositional system with volcano facies in Wubei sub-depression of Wuerxun depression;The fan delta system are divided into plain,front and front fan delta etc,three subfacies, seven microfacies; In distributary channel microfacies, sand conglomerate, gravel sandstone, middle-grit are main lithology, low maturity, poor sorting to medium, vertical sequence, visible bottom gravel and erosion surface, large scale cross-bedding are developed, partial visible horizontal bedding; channel mouth bar microfacies relatively rudimentary, lithology with sorting relatively good powdermiddle sandstone, development of small cross-bedding, horizontal bedding.