本研究考量了岩性、力學壓密和應力歷史對沉積岩孔隙率和滲透率的影響，利用TPCS-M1鑽井岩心的孔隙率和滲透率量測結果，建立應力歷史相依孔隙率及滲透率模型以計算TPCS-M1鑽井地層的孔隙率和滲透率。首先將TPCS-M1試體依粒徑分析結果把岩性劃分為四群(砂岩類、泥質砂岩類、砂質泥岩類及泥岩類)，其後量測各試體於不同有效圍壓下的孔隙率和滲透率，並建立此四群岩類的應力歷史相依孔隙率/滲透率模型，最後利用此模型計算鑽井地層的孔隙率和滲透率隨深度之變化。為檢驗計算所得的孔隙率結果之合理性，本研究蒐集井測之孔隙率資料並和計算結果進行比較。結果發現，砂岩類地層中，本研究計算之孔隙率非常接近中子井測/密度井測所推求的孔隙率(僅略低估於1 - 3 %)，而四種岩性的孔隙率計算結果則介於中子井測/密度井測與波速井測的推求結果之間。另外，本研究亦計算鑽井地層解壓至常壓下時的孔隙率，發現和台電報告中之常壓下影像孔隙率在各深度間隨岩性的跳動情形有大致相同的趨勢，以上顯示本研究以岩心試驗結果和應力歷史相依孔隙率模型，可合理估計砂岩孔隙率且可評估地層的孔隙率在各深度間隨岩性的變化趨勢。另一方面，本研究根據四群岩類之應力歷史相依孔隙率-滲透率關係方程式，可快速地從井測資料推算滲透率，並與透過試驗結果所計算的滲透率進行比較。結果發現，透過孔隙率-滲透率關係式所計算的滲透率，和利用試驗結果所計算的滲透率，在相同岩段下，其兩者差異不大，皆不超過一個數量級，但在不同岩段的滲透率卻相差甚鉅，顯示地層岩性的劃分與建立結果對於滲透率的推算有非常顯著的影響，因此若希望以上述兩種方法來推算地層滲透率隨深度的變化，則地層岩性的劃分與建立將為最重要的課題。;To calculate the porosity-depth and permeability-depth relationship in TPCS-M1 borehole, we establish the stress-history dependent porosity/permeability model of rock cores based on rock sample porosity/permeability measurements. First, we categorize the sedimentary lithology of each rock samples into four types (sandstone, muddy sandstone, sandy mudstone and mudstone) according to their pore size distribution information. Second, we measure the porosity/permeability of sedimentary rock samples under various effective confining pressure to establish the stress-history dependent porosity/permeability model for four types of sedimentary rocks. Last, we calculate the porosity-depth and permeability-depth relationship in TPCS-M1 borehole based on these model. To check if the calculated porosity is reasonable or not, we compare the calculated result with porosity derived from log and porosity derived from image of thin section. We find using porosity measurement from lab and stress-history dependent porosity model can well calculate the porosity in sandstone layer, and also can estimate the trend of porosity changing in depth with lithology. On the other hand, we use the porosity derived from log and stress-history dependent porosity-permeability relationship for four types of sedimentary rocks to quickly estimated the permeability, comparing with the calculated permeability. The result shows that, the permeability estimated by the stress-history dependent porosity-permeability relationship is always close to the permeability calculated by experimental data and stress-history dependent permeability model in the same layer (same lithology type and depth), but totally different in different layer, it indicates the result of categorizing and building the strata’s lithology will significantly influence the permeability estimated result. Thus, if we want to estimate the permeability-depth relationship by these two methods, the most critical issue will be how to well categorize and build the strata’s lithology.
