The Well-to-well Tracer Monitoring Interpretation Method Research And Application

Currently, exploration and development of high pore permeability reservoirs has come to the late, low porosity and permeability reservoirs become the focus of exploration and development. Judging from the development of effective, in low permeability oilfield with hypertonic oil, there is a big different:(1) lack of low permeability reservoir of natural energy in general, short-yield segment;(2) hard water flooding, the water injection effect is slow;(3) see after the water, water rose quickly;(4) final lower recovery. Therefore, need to strengthen research on seepage theory, analysis of seepage rule. Almost all of China’s onshore basins are developed to have low porosity and low permeability, low porosity and low permeability reservoir reserves annually accounts for more than half of China’s oil reserves. Low porosity and low permeability reservoir area, because the causes are complex, pore types, large differences exist on the physical properties and production capacity. Reservoir oil well in the late development low permeability, high water cut, well spacing between injected water flow distribution differences, there are advantages of channel, injected water sweep efficiency and recovery rate is low. To achieve improved efficiency and recovery injection wave and the emergence of a variety of water control programs and measures, before the design and implementation of these measures and methods, recognizing the heterogeneity of the reservoir is very important. Tracer test can effectively track the flow of formation fluids, and can reflect the heterogeneity of the reservoir characteristics, thus increasing attention.Inter-well tracer monitoring technology can reflect information includes:sweep efficiency, connectivity formation, and formation of the injected fluid compatibility, reflecting the effectiveness of measures and directional flow trends, these are only some of the qualitative information, in addition to the show through quantitative analysis of tracer data, can also reflect such as permeability, saturation and other parameters distribution in space. Generally low permeability reservoirs, reservoir porosity and permeability have a strong heterogeneity characteristic. Tracer tests tracer production curve can better reflect the heterogeneity, evaluation of programs, measures to deal with the effect of formation, according to the results of inter-well tracer monitoring, targeted for dynamically adjusting water. An important guiding significance for the development of reservoir description and yield adjustment program.In this paper, based on tracer monitoring theory, combined with numerical flow-line method, and applied to interpret tracer data between wells. Also discussed in detail the inter-well tracer flow mechanism and five-spot pattern of flow characteristics; discussed the impact of the tracer being adsorbed, well shape in the formation flow, vertical heterogeneity and other factors, as well as tracer by the flow in the wellbore pressure changes and the impact of produced water, etc.; convection-diffusion equation is derived tracer; single well explained in the original tracer is proposed based on the well group as a whole, for when tracer production curve to fit the entire group of wells, well integrated interpretation of reservoir parameters group (hypertonic bottom layer thickness, permeability, pore throat radius, etc.), to avoid the previous group of single well integrated well explained, there is a parameters of incompatibilities.The reservoir is divided into conventional reservoirs and permeability layer, using mathematical methods, mathematical models to build two reservoirs, set the upper and lower permeability layer parameters, randomly generated high permeability formation parameters within a limited range, get production wells tracer production curve tracer and tracer production curve and measured to fit. The results of the fitting, the computer automatically choose the best fit best formation parameter, parameter adjustment process to avoid the conventional manual method requires multiple parameters by virtue of experience.Fort Wu positions for low permeability oil reservoirs of the actual situation, expand research, provide a theoretical basis for the inter-well tracer low permeability reservoir testing; combined with geological data blocks Fort Wu positions and characteristics of oil wells producing dynamic data to develop inter-well tracer trace substances reasonable monitoring program. According to the principles of tracer screening, screening out the best tracer monitoring wells and determine the amount of tracer group needed; after the construction of wells for sampling and sample testing; research on the experimental test results, combined with monitoring of the range relevant information for each oil wells, injection wells and wells summed connectivity, the water advancing direction and speed, conditions and spread of injected water reservoir heterogeneity, evaluation of programs, measures to deal with the effect of formation (such as blocking water, profile, etc.), according to the inter-well tracer monitoring results, and carry out water dynamic adjustment; WU positions Fort tracer monitoring data block reservoir characteristics, established interpretation model, type and characteristics of the test curve summary.From the start of tracer flow mechanism, the establishment of inter-well tracer flow equations, by solving the tracer convection-diffusion equation, get well network tracer concentration breakthrough curves. Through the concentration of output curve explanation, according to the correlation between the concentration of the tracer reservoir system and reservoir parameters, fitting the theoretical concentration curve tracer concentration curve and actual output, anti-formation parameters obtained to evaluate the formation. On this basis, a mathematical model based on the calculation method, the preparation and interpretation software for low porosity and low permeability tracer production curve, and explain the actual well group analysis. Through inter-well tracer interpretation software, data can be provided for the production site include:waterline forward speed, the injected water distribution ratio, swept volume of fluid injected, spread rate, permeability layer parameters, combined with low oil region Wu Fort hole positions low permeability reservoir characteristics, and to interpret test data, interpretation of the results in line with actual production, to verify the applicability of the tracer and tracer interpretation of monitoring data interpretation software warehouse in Fort Wu low permeability oil reservoirs.