Reservoir Characterization Of Volcanic Reservoirs In Shengping Gas Field

Shengping gas field locates in the Anda, Heilongjiang province. The formationis in the faulted area southeast of Songliao basin, north of Xujiaweizi faulted structure.With the discovery of deep natural gas resources in the Songliao basin, the volcanicrocks exploration in the Shengping gas field has made a great progress, making thevolcanic rock hydrocarbon reservoir become a new hot spot on the study of China’seastern oil and gas reservoir.Volcanic rocks of Yingcheng formation form the main reservoir in Shengping gasfield, which have a good exploration potential and would become the main area indeep natural gas exploration in Daqing filed. Through a lot of geological, logging andseismic data, the stratigraphic division and correlation, lithology identification andreservoir prediction have been made. We also conduct the analysis and research indetails on the volcanic reservoir space and diagenesis, reservoir classificationevaluation and gas-bearing properties, volcanic rocks reservoir modeling.The results of the study show that:1. According to the lithological and electrical characteristics, the volcanic rockshave been divided into four eruption cycle. The corresponding lithofacies consist ofoutbreak, overflow and sedimentary face. On basis of single well analysis, combinedwith reservoir reconstruction technique and sparse pulse inversion method, invertingthe wave impedance, density, resistivity, natural gamma data. Using the aboveparameters, through the mutual constraint of the wave impedance, density, andelectrical resistivity, calculate reservoir density, and predict the reservoir quality.2. There are three types of pore in volcanic rocks reservoir, stomatal, porous andcrack-porous. From the reservoir space and pore connecting situation, the stomatal isthe best, porous type generally, the crack-porous type is the worst. Structural fracturesand all kinds of pore space connected constitute throats, which is the structure featureof this kind reservoir. Rock reservoir property heterogeneity is very serious. Thecombination of Microcrack and stomatal type is the main gas reservoirs3. Reservoir space main develops in the top or bottom of volcanic eruption andoverflow phase, mainly with intergranular pore, expanding original porosity due todissolution, and solution pores.