The Distribution Regulation Of Shallow Buried Gas In South Of Daqing Changyuan And The Prediction Studies Of Formation Pressure On Its Adjusted Well Site

For many years, Putaohua oil layer in the south of Daqing placanticline Putaohua–Aunan oil field has had the following problem frequently in drilling。(1) Heidimiao was grew shallow gas zone, buried depth was shallow, shallowly gas was made flees in a big way and extremely easy to has the shallow gas zone accident. (2) Putaohua oil field water-injection development has nearly 20years, created the subsurface pressure to be unusual, in well drilling oil gas water immersed complex situation occurred sometimes; (3) Heidimiao shallowly gas and Putaohua level highly pressure caused the well cementation quality to guarantee in difficulty.This article conbined with the above questions, take the Putaohua,Aobaota oil field as the research object, carried on the detailed geology research about Putaohuaoil layer shallow layer gas has in Daqing placanticline,take a great quantity of on-site testing material as the foundation, Through the development of fine geology research to make the analysis of dynamic and static geology, in order to make a research of distribution rule of the work area shallow gas zone and the method of forecasting Putaohua reservoir pressure . The research indicated that (1) Most of the shallow gas zone vertical growth section were centralized in the lower of n4 to the upside of n3 formations, the well depth are 320 - 550m. (2) shallow gas zone mainly distributes in the local structural high point and the updip point in the lowered(3) The Aobaota oil field Heidimiao shallow gas zone is the lothological - structure gas pool. The structural factor plays the decisive role in oil accumulation , the fault cooperates with the structural high spot form the structural trap is advantaged to natural gas gathering; At the same time, the lothological factor take a certain function in gas zone distribution, makes the distribution in shallow gas zone to be more difficult.In determining the distribution of Putaohua oil layer shallow gas zone in southern oilfields in Placanticline, based on the rational use of drilling fluid density program . Using by low-permeability reservoir pressure conduction empirical formula,has been developed pressure prediction methods of Putaohua layer in the southern Placanticline to reduce drilling risks, improve the instruction function in geological design to the well drilling production, in ensuring that the well drilling production smoothly to carry on..