Study Sedimentary Characteristics And Reservoir Heterogeneity Of The Lianhua Oil Shahejie Formation In Qi-40 Area

As an important part of the reservoir studying, Reservoir characteristics of the research has been very significant. Reservoir heterogeneity refers to a compound refers to the impact of oil and gas reservoirs in the role of deposition, diagenesis and post construction, spatial distribution of the reservoir as well as a variety of non-uniform internal change different attributes.On the basis of more in-depth research on the heterogeneity of reservoir, there are many features that we can find out the status of the reservoir, and then on this basis we can make updates and better oil and gas exploration program. This can first understand the actual situation of production; secondly, this may be a reasonable choice for the exploration and development of the field development wells to make a more realistic option, and yet in all respects under the conditions of mature design a reasonable enhance oil recovery programs.As one of the largest blocks of the size of the current implementation of steam flooding, Liaohe Oilfield Qi 40 block has been considerable major role and significance. Since 1998, Sarkozy has gone through the guide block 40, the expansion of both the experimental stage, and industrial application.2006 began the construction of large-scale industrial transfer steam flooding, in March 2008, a total of 139 wells completed turn drive group, the block into a comprehensive industrial development of steam flooding. In 2011, this block had production of 600,000 tons of crude oil, 500,000 tons more than the original way to increase gradually into the stable phase. So far, Sarkozy late 40 body parts have been flooding in the vapor phase, the overall downward trend in production. With the deepening and development of steam drive continuous improvement maturity, subject to the constraints of the reservoir heterogeneity, steam injection in the long-term development process, often uneven phenomenon vapor absorption, high, low permeability layer A Steam large differences in the longitudinal direction, so that the oil and gas reservoirs in some parts of the formation of the channel has a low resistance permeability characteristics, injecting steam along this channel can be in a "barrier" in circulation, the formation of distinct advantages onrush, the gradual formation of steam flooding advantage aisle.Qi 40 fan delta region is deposited, Due to heavy oil exploitation belong, Its physical properties and other characteristics are obvious differences, understand their reservoir characteristics, provide a theoretical basis for the overall development effectiveness improve these aspects for improving recovery and development effects have a very significant role. Therefore, understanding the reservoir heterogeneity of the study area characteristics is necessary for providing the basis for future reservoir evaluation and further exploration and development.according to the reservoir static and dynamic data to determine the stratigraphic division standard of Lianhua reservoir in all 40 areas, with a small layer as a unit to complete the division and correlation of strata, the modern sedimentology theory, comprehensive application of core, logging, well logging data, the use of "cycle control,classification of principle, to determine the 2 sets of oil group,6 sets of sand group,16 small layer model. The L1,L2 selected 4 small layer of sandstone is the main reservoir of Lianhua oil layer thickness is relatively large. So wechoose one of four small layer as the main sedimentary facies study.study the sedimentary model of Lianhua reservoir in District 40, single sand layer as the unit of sedimentary microfacies research, describe the different microfacies characteristics and to analyze the relationship between the phase of reservoir; system analysis and Research on reservoir sedimentary phase by using the core data, logging curve, the western region as the main object of lotus hill reservoir sediment source area. Lianhua reservoir in all 40 district is deposited in front subfacies of fan delta depositional system, mainly include subaqueous distributary channel, channel edge and tributaries Bay microfacies. On the basis of sedimentary microfacies, sand body macro analysis of the distribution characteristics, understand the reservoir sand body geometry, spatial and temporal distribution characteristics.In this paper, the basic characteristics of reservoir geology, depositional systems and sedimentary micro facies, reservoir heterogeneities special features and other aspects of the system were studied, and some of the main findings are as follows:(1)Application of the second division of the vertical sand, mud sandwich recognition method to carry out sand causes cell division and correlation of the main small layers, each layer are divided into small 2, a total of eight causes of sand.(2) Through detailed study of reservoir sedimentary facies that Qi 40 blocks 65 oil wells set for Lotus fan delta front deposits its internal reservoir identification of underwater distributary channel, river edge, between the Bay tributaries microfacies, clear spatial distribution characteristics of sedimentary microfacies.(3) Study heterogeneity within the layers show:the study area are mainly developed rhythm, rhythm and homogeneous composite are three vertical rhythm rhythm patterns, such as anti-rhythm rare. The coefficient of variation within, onrush coefficient, and other parameters, as reflected in poor permeability heterogeneity are weak degree of heterogeneity. A reservoir sandstone lotus sandwich thickness and greater frequency, continuity is good; bad sandwich lotus two reservoir continuity, scattered distribution.(4) Statistical key small layer stratification coefficient and permeability sandstone density variation coefficient, onrush coefficient, range and other parameters of the show:a reservoir between lotus heterogeneity is a weak degree of heterogeneity; the lotus is a weak two reservoirs to moderate degree of heterogeneity. Compartments in the study area of the target layer distribution is stable, the approximate range of thickness is 2-4m, is a weak to moderate degree of heterogeneity.(5) Plane heterogeneity research results show:Lotus I oil sands drilling rate is relatively low, poor connectivity, lotus II oil sands larger lateral continuity is good. Statistical coefficient of variation coefficient onrush lotus I reservoir parameters also show a weak degree of heterogeneity, lotus II oil is a weak-moderate heterogeneity.