Abstract:

Fluid-rock interaction accompanied by inspissation of fluids can make significant effects on hydrocarbon formation. According to integrated data of rock section, test analysis, geostatistics, on the basis of study on water consumption of main mineral alteration during diagenetic stage, water consumption of sandstone reservoir of Paleogene during diagenetic stage in the Dongying sag is integrally evaluated. Research results show that water consumption function is general phenomenon in the Dongying sag. Kaolinization of feldspar is mainly water consumption reaction. Average quantity of total water consumption is 38.3 Gt.Vertically, there are obviously two peak sectors of feldspar transformation ratio and water consumption quantity, namely shallow sector (from 1,200 to 2,000 m) and deep sector(from 2,000 to 3,500 m). Horizontally, different districts of the Dongying sag vary in water consumption quantity; feldspar transformation ratio and water consumption quantity per unit sandstone volume of shallow sector in southern gentle slope and northern steep slope are greater than those of deep sector; on the other hand, those of deep sector in subsag are greater than those of shallow sector. Since sandbody volume of deep sector is bigger, its water consumption quantity, especially in subsag, is great.

Key words:  diagenesis, water consumption function, feldspar, kaolinite, Dongying sag