Porosity interpretation method based on condition of tight oil reservoir variable skeleton parameter

Abstract

The invention provides a porosity interpretation method based on the condition of tight oil reservoir variable skeleton parameter. The porosity interpretation method based on the condition of the tight oil reservoir variable skeleton parameter comprises the steps that core of the tight oil reservoir is restored first, effective analysis data of the effective core porosity of the tight oil reservoir is selected, the clay mineral content, rock constituents (arenaceous, calcareous and dolomitic are included mainly) and the porosity characteristics in the tight oil reservoir of the effective core and the corresponding responding characteristics of natural gamma-ray logging relative parameter (delta GR), acoustic travel time logging parameter (delta t), density logging parameter (Rho b) and neutron logging parameter (phi N) are contrastively analyzed, the affect of the oil-bearing property of the tight oil reservoir for the logging parameter is ignored, a porosity logging interpretation model based on the condition of the tight oil reservoir variable skeleton parameter is built, and a porosity logging interpretation method to be determined under the condition of tight oil reservoir variable skeleton parameter is formed. The porosity interpretation method based on the condition of the tight oil reservoir variable skeleton parameter is helpful to improve the tight oil reservoir porosity logging interpretation precision.

Description

technical field [0001] The invention belongs to the technical field of prospecting and logging, and in particular relates to a porosity interpretation method based on variable skeleton parameters of tight oil reservoirs. Background technique [0002] Tight oil refers to oil resources from tight reservoirs (siltstone, sandstone, limestone, dolomite, etc.) other than shale. At present, the United States has successfully achieved a breakthrough in the exploration and development of tight oil, showing good development prospects. Tight oil is also widely distributed in major oil and gas-bearing basins in China, mainly developing tight sandstone oil or tight carbonate oil that coexists or contacts with lacustrine source rocks and is widely distributed. Tight oil exploration is an important successor area for oil and gas exploration, but due to Due to the special reservoir geological background of tight oil formation, the reservoir rock composition is complex and variable, which l...

AI Technical Summary

Problems solved by technology

According to the porosity and X-ray diffraction analysis data of the reservoir cores of the IV sand group, the porosity is generally 0.3%-10.4% (mainly 2.0-6.5%), the content of clay minerals is generally 5.5%-49.9%, quartz, feldspar and rock The total clastic content is generally 12.5-77.9%, the calcareous content is generally 0.0%-58.1%, and the dolomitic content is generally 0.0%-48.8%. The lithology of tight oil reservoirs is mainly clastic rock, chemical rock and transitional types. Complex and changeable rock types will inevitably lead to changeable and difficult to determine logging skeleton parameters

Corresponding analysis of tight oil reservoir core analysis porosity and logging acoustic time difference, density, and neutron logging parameters, based on the zero porosity skeleton parameter selection method, processing to obtain reservoir rock skeleton acoustic time difference, skeleton density, and skeleton neutron parameters 164~197μs / m (mainly 175~195μs / m), 2.65~2.83g / cm 3 (Mainly 2.67~2.79g / cm 3 ), -2 to 12.0p.u (mainly 2.5 to 9.0p.u), skeleton parameters vary widely with depth and are difficult to determine, affecting the porosity logging prediction accuracy