水淹层解释评价技术在葡北区块的应用

Application of interpretation and evaluation technology for watered-out zones in Pubei Block.

大庆外围油田指分布在大庆油田周围市县的小区块油田,多属于低孔渗油藏,储集层中油水分布受构造、岩性及断层等因素控制,经过几十年注水开发后,油水关系更加复杂,水淹层解释更加困难。葡萄花油田属大庆外围油田,葡北区块位于葡萄花油田穹窿状构造北部,主力产区主要为一断块128井区和葡北108井区,储集层平均空气渗透率90mD,有效孔隙度23.6%,属于低渗透储集层。为提高葡北区块解释精度,根据葡北区块已投产井资料,以井壁取心岩石热解、热解气相色谱、荧光显微图像资料为基础,建立了该区块评价低渗透油层水淹程度的岩石热解剩余油饱和度与测井有效孔隙度的图板法、热解气相色谱的谱图法和荧光显微图像分析的图像法3种评价方法。应用表明效果较好,可作葡北区块水淹层解释评价的有效方法。

Daqing periphery oilfields refer to the small block oilfields distributed in the cities and counties around Daqing Oilfield,which are mostly low porosity and permeability reservoirs,the oil and water distribution in reservoirs is affected by controlling factors,such as,structures,lithology and faults.After decades of water flooding,oil-water relationship is more complex,the interpretation for water-flooded zones is more difficult.Putaohua Oilfield is on the peripheral of Daqing Oilfield and Pubei Block is located in the north of the domal structure in Putaohua Oilfield,its main oil regions are Fault Block 128well area and Pubei 108well area,average air permeability of the reservoirs is 90mD,effective porosity is 23.6%,so they belong to low-permeability reservoirs.To improve the interpreting accuracy in Pubei Block,according to the data of the wells that have been put into production in Pubei Block and taking sidewall coring rock pyrolysis,pyrolysis gas chromatogram and fluorescence microscopic image data as the bases,the author set up three methods to evaluate water flooded degrees of Pubei Block′s low permeability reservoirs,they are:the chart of rock pyrolysis residual oil saturation and wireline logging effective porosity,spectra method of pyrolysis gas chromatogram and analysis method of fluorescence microscopic image.The application showed better results and the methods can effectively interpret and evaluate watered-out zones in Pubei Block.