The Application of Performance Analyses of Oil and Water Wells in Reservoir Simulation of Complicated Fault Block Sandstone Reservoir Which Contains A Hydraulic Fracture
Authors: Jiang Tingxue , Lang Zhaoxin , Shan Wenwen , Wang Fengjiang 
Published: December 2007

The characters of complicated fault block sandstone reservoirs are:Theheterogeneity and anisotropy of formation are very severe, and there are greatchanges of lithology and physical properties just within offset wells;theremay be a certain degree of changes in fracture azimuth within the scope ofadjacent wells;well network of irregular area injection is mainly used andVarious treatment measures are frequent so that it is very difficult toanalyze the production data.

In order to exploit the reservoirs in scientific, reasonable and high efficient way, the common production data are used as wellas the data of geology, testing, well logging, rock core, laboratory data, andanalysis of seepage flowing theory may also be needed to conduct the following studies:Determination of the boundary of calculating element (closedboundary);re-evaluation and confirmation of equilibrium data withincalculating element;Analyses of the reasons of minor production, productionreduction and injection reduction of wells;Estimation of azimuth ofhydraulic fracture;Determination of object function of optimum fracturingdesign;Estimation of anisotropy;Distributing ratio of production andinjection andQuantitative evaluation of formation interconnection.

It hasvery significant meaning to take hold of the present state of the reservoirstruly, to confirm and adjust parameters of reservoir simulation and to predictreservoir performance scientifically, etc. The technology has been verified in 2reservoirs located in north China, and has been developed and perfected inlater time. Now, it is a maturated system which may be applied in more oilfields and a great deal of benefits may be expected.

Introduction

There are many complicated fault block reservoirs with low permeability inchina as a result of its intrinsic character of terrestrial deposit and thefrequent movement of earth crust. The overall character of the complicatedfault block reservoirs is their crushed structure which brings about above fouroutstanding features, which result in more difficulty in development than thoseof integral ones. Therefore, it is very important to use the reservoirsimulation technique in order to exploit such reservoirs in scientific andeffective way.

It is very crucial to abstain key input parameters more reliable in thereservoir numerical simulation. In integral structure reservoirs, only severalrepresentative wells whose data is relatively complete is just enough. However, it is very complicated and undetermined in collecting data in crusted andcomplicated fault block reservoirs, for no well can represent the wholereservoirs. On the other hand, it is impossible to conduct expensive tests oncore or any other experiments in every little block reservoir as a result ofeconomic considerations. Consequently, the key problem is how to make full useof various ordinary data, and to evaluate and determine several subjectparameters needed by reservoir numerical simulation in most economic andeffective way so that the real reservoir present state and a scientificreservoirs performance as well as the reservoirs' development and theiradjusting and various treatments evaluations are available.

Therefore, 8 above research works have been conducted in the paper with thehelp of common monthly production and injection report data combined with onesof geology, well logging and well test etc. What's must be noted that the ideaand the method of above basic work is adaptable in various development stages, so, with which the update performance of the reservoirs is available and theinstructions of the next work arrangement may be put forward. So, in the longrun, the research work has practical meaning for the high effective developmentand adjustment of complicated fault block reservoirs.