A Novel Method of Non-Darcy Well Test Interpretation for Ultra-Low Permeability Reservoirs

2020 ◽  
Author(s):  
Li Li ◽  
Wei Liang ◽  
Zhenghe Yan ◽  
Kun Wang ◽  
Qiyuan Luo ◽  
...  
Keyword(s):  
Low Permeability ◽  
Test Interpretation ◽  
Well Test ◽  
Novel Method ◽  
Low Permeability Reservoirs

Study on Test Cycle of Build-up Well Test in Low Permeability Reservoir

2012 ◽  
Vol 594-597 ◽  
pp. 456-459
Author(s):  
Tong Jing Liu ◽  
Bao Yi Jiang ◽  
Rui Liu ◽  
Peng Xiang Diwu
Keyword(s):  
Reservoir Engineering ◽  
Low Permeability ◽  
Actual Process ◽  
Test Interpretation ◽  
Well Test ◽  
Test Cycle ◽  
Main Research ◽  
Low Permeability Reservoir ◽  
Production Wells ◽  
Low Permeability Reservoirs

The speed of development of well test technology has been faster than well test interpretation technology in low permeability reservoirs. One of the main research directions for well test soft technology was specific interpretation theory and interpretation techniques. In recent years, well test was put forward higher request by the production complex and low permeability reservoirs. Test interpretation results urgently need to be applied to reservoir engineering analysis in-depth and quantitatively. One of the limited reality conditions of well test application was lack of the comprehensive research combined with the reservoir engineering. Combining with the test examples, the investigation radius change between injection-production wells was studied, and the build-up well test cycle in low permeability reservoir was optimized. According to the actual process situation, it was proposed that take 20d as the upper limit of well test cycle, and 10d block as the lower limit of well test cycle of build-up well test in a typical low permeability reservoir.

Application of Pressure-Rate Deconvolution to Well Test Interpretation of Low Permeability Reservoirs

2011 ◽  
Vol 383-390 ◽  
pp. 243-247
Author(s):  
Ying Hao Shen ◽  
Shun Li He ◽  
Hong Ling Zhang
Keyword(s):  
Solution Algorithm ◽  
Test Sequence ◽  
Low Permeability ◽  
Test Interpretation ◽  
Well Test ◽  
Deconvolution Method ◽  
Robust Solution ◽  
Deconvolution Algorithm ◽  
Low Permeability Reservoirs

Pressure-rate deconvolution method based on the newly robust solution algorithm is applied to low permeability reservoirs, and deconvolution codes were developed for the study based on Schreoter deconvolution algorithm in this paper. The application of this method in a low permeability oilfield shows that deconvolution can provide much more information than the conventional well test interpretation methods, and this deconvolution method can interpret the whole test sequence but doesn’t be limited in pressure build-up period. It is proved that the pressure-rate deconvolution algorithm works well in well test interpretation of low permeability reservoirs.

scholarly journals A New Method for Research on Unsteady Pressure Dynamics and Productivity of Ultralow-Permeability Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Kun Wang ◽  
Li Li ◽  
Xiao Chen ◽  
Wei Liang ◽  
Yong Yang ◽  
...  
Keyword(s):  
Stress Sensitivity ◽  
Low Permeability ◽  
Threshold Pressure ◽  
Test Interpretation ◽  
Well Test ◽  
Pressure Derivative ◽  
Threshold Pressure Gradient ◽  
The Real ◽  
Skin Factor ◽  
Low Permeability Reservoirs

In the numerous low-permeability reservoirs, knowing the real productivity of the reservoir became one of the most important steps in its exploitation. However, the value of permeability interpreted by a conventional well-test method is far lower than logging, which further leads to an inaccurate skin factor. This skin factor cannot match the real production situation and will mislead engineer to do an inappropriate development strategy of the oilfield. In order to solve this problem, key parameters affecting the skin factor need to be found. Based on the real core experiment and digital core experiment results, stress sensitivity and threshold pressure gradient are verified to be the most influential factors in the production of low-permeability reservoirs. On that basis, instead of a constant skin factor, a well-test interpretation mathematical model is established by defining and using a time-varying skin factor. The time-varying skin factor changes with the change of stress sensitivity and threshold pressure gradient. In this model, the Laplace transform is used to solve the Laplace space solution, and the Stehfest numerical inversion is used to calculate the real space solution. Then, the double logarithmic chart of dimensionless borehole wall pressure and pressure derivative changing with dimensionless time is drawn. The influences of parameters in expressions including stress sensitivity, threshold pressure, and variable skin factor on pressure and pressure derivative and productivity are analyzed, respectively. At last, the method is applied to the well-test interpretation of low-permeability oil fields in the eastern South China Sea. The interpretation results turn out to be reasonable and can truly reflect the situation of low-permeability reservoirs, which can give guidance to the rational development of low-permeability reservoirs.

On the selection of suitable operate durations for injection tests in low permeability reservoirs

2020 ◽  
Vol 6 (1) ◽  
pp. 135-149
Author(s):  
Guzyal F. Asalkhuzina ◽  
Alfred Ya. Davletbaev ◽  
Ildus L. Khabibullin ◽  
Rina R. Akhmetova
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Low Permeability ◽  
Reservoir Pressure ◽  
Well Test ◽  
Injection Wells ◽  
Fluid Filtration ◽  
Operating Modes ◽  
Low Permeability Reservoirs ◽  
Injection Modes

The article discusses the aspects of conducting and analyzing the results of hydrodynamic studies of wells (well test) at steady-state injection modes conducted in injection wells in order to assess reservoir pressure and injectivity. The main goal of this work is to determine the necessary duration of injection modes at which reservoir pressure will be determined at the maximum research radius. In view of the considerable duration of the study, in low-permeability reservoirs, the work of the environment wells is taken into account, which, in the process of well research, should have a minimal impact on the results of data interpretation. To this end, we simulated the dynamics of pressure changes for this type of well test for various parameters of the reservoir and the duration of injection modes, taking into account the influence of the work of the surrounding production wells. To solve this problem, we used a numerical model of fluid filtration in an element of a nine-point development system in a low-permeable reservoir. The production and injection of fluid is carried out in wells with main technogenic fractures of hydraulic fracturing. During the simulation, the filtration parameters of the “fracture-formation” system and the duration of the well operating modes were varied, and synthetic data on the change in pressure in the wells were reproduced. Pressure and flow rates at the well operating modes were analyzed by plotting the indicator diagram (ID). Estimates of the extrapolated pressure from the ID graphs were compared with the pressures in the numerical model, in particular, the pressure on the supply circuit and on the study radius. It is shown that for low-permeability formations when studying injection wells using the steady-state injection method, it is necessary to take into account the research radius, which depends on the permeability of the formation and the duration of the injection regimes. Also, the research radius must be taken into account when constructing isobar maps along with the reservoir pressure value.

Variable-Permeability Well Test Model and Pressure Response of Non-Darcy Flow in Low-Permeability Reservoirs

2014 ◽  
Vol 644-650 ◽  
pp. 5097-5100
Author(s):  
Xiao Lei ◽  
Mu Wang Wu ◽  
Feng Bo Zhang ◽  
Shuang Qi Liu ◽  
Yao Quan Xiang ◽  
...  
Keyword(s):  
Boundary Effect ◽  
Darcy Flow ◽  
Low Permeability ◽  
Test Model ◽  
Well Test ◽  
Pressure Derivative ◽  
Variable Permeability ◽  
Set Up ◽  
Low Permeability Reservoirs ◽  
Well Test Model

Considering the variable-permeability effect of non-Darcy flow in low-permeability reservoirs, this work set up a two-dimensional model with boundaries. The implicit finite difference algorithm was employed to solve the well test model, and typical curves in log-log scale by considering the effects of variable-permeability and non-Darcy flow were obtained. The results show that, in reservoirs with impermeable boundary, the upturned part of the pressure derivative curve caused by boundary effect will be covered by that of non-Darcy effect, indicating boundary effect is postponed to appear. The more of the non-Darcy effects result in less obvious upturn of the typical curves. The upturn of typical curves and the effect of boundary are enhanced by increasing the numbers of impermeable boundaries or by decreasing the distance from the well to the boundary.

ASSESSMENT OF OIL WELL PRODUCTIVITY IN LOW-PERMEABILITY RESERVOIRS IN THE FIELDS OF EASTERN SIBERIA

2017 ◽  
pp. 30-36
Author(s):  
R. V. Urvantsev ◽  
S. E. Cheban
Keyword(s):  
Oil Recovery ◽  
Large Scale ◽  
Oil And Gas ◽  
Oil Extraction ◽  
Low Permeability ◽  
Oil Well ◽  
Eastern Siberia ◽  
Development Costs ◽  
Traditional Fields ◽  
Low Permeability Reservoirs

The 21st century witnessed the development of the oil extraction industry in Russia due to the intensifica- tion of its production at the existing traditional fields of Western Siberia, the Volga region and other oil-extracting regions, and due discovering new oil and gas provinces. At that time the path to the development of fields in Eastern Siberia was already paved. The large-scale discoveries of a number of fields made here in the 70s-80s of the 20th century are only being developed now. The process of development itself is rather slow in view of a number of reasons. Create a problem of high cost value of oil extraction in the region. One of the major tasks is obtaining the maximum oil recovery factor while reducing the development costs. The carbonate layer lying within the Katangsky suite is low-permeability, and its inventories are categorised as hard to recover. Now, the object is at a stage of trial development,which foregrounds researches on selecting the effective methods of oil extraction.

Sign in / Sign up

Export Citation Format

Share Document