Integrating Experience and Developing Recommendations to Aid inFormation Testing Jobs Planning in Various Geological Conditions

摘要

The objective of this work is to summarize obtained information during the well formation testing(WFT)jobs completed in open hole at the fields of PJSC NOVATEK.We also conducted analysis of formationpressure measurements,assessment of the saturating fluid type and the quality of downhole fluid samplescollected at various geological and well conditions.Now PJSC NOVATEK and its subsidiaries have beenactively using various types of WFT to solve a complex geological objective on the fields at exploration anddevelopment steps.Thus,an impressive array of data was formed,and detailed analysis made it possible todevelop optimal success criteria and recommendations for carrying out such jobs in the wells.We used data obtained with WFT jobs in the main productive reservoirs of the Cenomanian,Marseilian,Tanopchin and Achimov strata in the northern region of Western Siberia.We have considered influence of various geological and technological factors on the reliability onformation pressures(FP)measurements with WFT.To assess the quality of downhole fluid analysis(DFA)we tried to compare time to reservoir fluid appearance,reservoir properties,drilling fluid type etc.,independence of sampling tool type utilized.Within performed interval pressure transient tests(IPTT)an analysis of the quality of the hydrodynamicparameters of the reservoirs was conducted aiding to plan cased hole well-tests.We also considered of WFT application for representative downhole sampling to obtain information ofthe main PVT properties of reservoir fluids.