Application of Oil/gas Well Fire-burning Wrecking Technology on Oil Production Platform Hainan-2
Authors: Ma Zongjin , Yang Lingrui , Xiao Runde 
Published: December 2007

In the period of maturing oil field development, on one hand, water saturation becomes higher and higher, on the other hand, lots of moveable oil still stays in the reservoir. The main reason for this case is determined by the variation of the reservoir, so the main job for geologists is to know the heterogeneity and continuity of the reservoir. In this case, the well spaces are about 200-300 meters. In order to give a relatively reliable prediction of the reservoir variation between wells, we must build a prototype model and know the real condition of the reservoir. During the past 5 years, we have studied the fan-delta outcrop and built a very detailed prototype model and established sets of geological knowledge databases, which include lithology database, microfacies database, sandbody scale database and many geological statistic databases.

According to these useful databases, we can predict the heterogeneity and oil saturation of maturing oilfield in different blocks and different layers. A few wells have been drilled according to our prediction through prototype model, and the oil saturation is 5-7 times higher than the old wells. Prototype model is very useful in the oilfield reservoir heterogeneity prediction, which have the same or similar depositional environment. In order to predict the reservoir variation of different depositional reservoir, series of prototype models must be built.

Introduction

The content of establishing geological knowledge database developed at the same time with the foundation of geology and especially the reservoir geology, it becomes more complete and perfect along with the other disciplinary continuous development. But the conception of geological knowledge database was shaped from the content studied by geology and its research achievement only decade ago. As we know, the direct subsurface information received from drilling core and the indirect information from the logging record amount to only tiny percent of the total formation volume. Seismic explanation can describe the 3-D characteristics of reservoir in theory. But the vertical resolution can't satisfy the development. In this situation, to predict the 3-D characteristics of reservoir from the finite data, geologists must establish detailed reservoir geological knowledge database about such type of depositional system and depend on it, a practicable reservoir prediction method. So, the construction of reservoir geological knowledge database is basic for underground reservoir precise prediction between wells in oilfield and is also the key to establish accurate geological model.

The reservoir geological knowledge database is referred to the general parameter that generated and derived from the multitude of researches which can quantitatively and qualitatively express the geological characteristics of different genetic reservoir units and can predict the similar sedimentary system. It can be used to guide the researching, predicting and modeling of studying reservoir. For example, the shape of different genetic units is a qualitative geological knowledge database; and the W/T ratio of channel sandbody is a quantitative geological knowledge database.

The methods to require geological knowledge database is numerous, but the most important are the detailed research from the outcrop, modern deposition and the dense well pattern in oil field. The outcrop is much superior to other methods for constructing the geological knowledge database because of its distinguishing features.