scholarly journals A Semi-Analytical Pressure-Transient Model to Detect Inter-well Interference of Multi-Well-Pad-Production Scheme in Shale Gas Reservoirs

2018 ◽  
Vol 73 ◽  
pp. 8
Author(s):  
Leng Tian ◽  
Cong Xiao ◽  
Yu Dai
Keyword(s):  
Transient Response ◽  
Shale Gas ◽  
Flow Regimes ◽  
Stress Sensitivity ◽  
Transient Model ◽  
Pressure Transient ◽  
Fracture Spacing ◽  
Fracture Length ◽  
Well Spacing ◽  
Well Pattern

Recently, Multi-Well-Pad-Production (MWPP) scheme has been in the center of attention as a promising technology to improve Shale Gas (SG) recovery. However, Inter-Well Pressure Interference (IWPI) induced by MWPP scheme severely distorts flow regimes, which strongly challenges the traditional pressure-transient analysis methods, which focus on Single Multi-Fractured Horizontal Wells (SMFHW) without IWPI. Therefore, a methodology to identify pressure-transient response of MWPP scheme without and with IWPI is urgent. To fill this gap, by utilizing superposition theory, Gauss elimination and Stehfest numerical algorithm, the pressure-transient solution of MWPP scheme was established, as a result, type flow regimes can be identified by considering MWIP. Our results show that our proposed model demonstrates promising calculation speed and acceptable accuracy compared to numerical simulation. Part of flow regimes are significantly distorted by IWPI. In addition, well rate mainly determines the distortion of pressure curves, while fracture length, well spacing, fracture spacing mainly determine when the IWPI occurs. The smaller the gas rate, the more severely flow regimes are distorted. As the well spacing increases, fracture length decreases, fracture spacing decreases, occurrence of IWPI becomes later. Stress sensitivity coefficient approximately has no influences on distortion of pressure curves and occurrence of IWPI. This work gains some additional insights on pressure-transient response for MWPP scheme in SG reservoir, which can provide considerable guidance on fracture properties estimation as well as well pattern optimization for MWPP scheme.

A Semianalytical Methodology for Pressure-Transient Analysis of Multiwell-Pad-Production Scheme in Shale Gas Reservoirs, Part 1: New Insights Into Flow Regimes and Multiwell Interference

SPE Journal ◽  
2017 ◽  
Vol 23 (03) ◽  
pp. 885-905 ◽  
Author(s):  
Cong Xiao ◽  
Yu Dai ◽  
Leng Tian ◽  
Haixiang Lin ◽  
Yayun Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Regime ◽  
Transient Response ◽  
Shale Gas ◽  
Transient Analysis ◽  
Flow Regimes ◽  
Pressure Transient ◽  
Fracture Spacing ◽  
Fracture Length ◽  
Well Spacing

Summary Recently, a multiwell-pad-production (MWPP) scheme has been the center of attention as a promising technology to improve shale-gas (SG) recovery. However, the increasing possibility of multiwell pressure interference (MWPI) in the MWPP scheme severely distorts flow regimes, which strongly challenges the traditional pressure-transient analysis methods that focus on single multifractured horizontal wells (SMFHWs) without MWPI. Therefore, a methodology to identify pressure-transient response of the MWPP scheme with and without MWPI is urgent. To fill this gap, a new semianalytical pressure-transient model of the MWPP scheme is established by use of superposition theory, Gauss elimination, and the Stehfest numerical algorithm. Type curves are generated, and flow regimes are identified by considering MWPI. Finally, a sensitivity analysis is conducted. Our results show that there are good agreements between our proposed model and numerical simulation; moreover, our semianalytical approach also demonstrates a promising calculation speed compared with numerical simulation. Some expected flow regimes are significantly distorted by MWPI. In addition, well rate determines the distortion of pressure curves, whereas fracture length, well spacing, and fracture spacing determine when the MWPI occurs. The smaller the gas rate, the more severely flow regimes are distorted. As the well spacing increases, fracture length decreases, fracture spacing decreases, and the occurrence of MWPI occurs later. The stress-sensitivity coefficient has little to no influence on the occurrence of MWPI. Similar to the concept of the dual-porosity model, three new flow regimes—the single-well flow regime, MWPI flow regime, and MWPP flow regime—are artificially defined to systematically characterize the flow regimes of the MWPP scheme. This work offers some additional insights on pressure-transient response for the MWPP scheme in the SG reservoir, which can provide considerable guidance for fracture-properties estimation and well-pattern optimization for the MWPP scheme.

A Comprehensive Model Integrating the Stress Sensitivity for Pressure Transient Behavior Study on the Two-Zone System for Offshore Loose Sandstone Reservoirs

2021 ◽  
Author(s):  
Chong Cao ◽  
Linsong Cheng ◽  
Xiangyang Zhang ◽  
Pin Jia ◽  
Wenpei Lu
Keyword(s):  
Flow Regimes ◽  
Transient Behavior ◽  
Stress Sensitivity ◽  
Composite Model ◽  
Zone Model ◽  
Well Testing ◽  
Comprehensive Model ◽  
Pressure Transient ◽  
Sandstone Reservoirs ◽  
Sandstone Formation

Abstract Permeability changes in the weakly consolidated sandstone formation, caused by sand migration, has a serious impact on the interpretation of well testing and production prediction. In this article, a two-zone comprehensive model is presented to describe the changes in permeability by integrating the produced sand, stress sensitivity characteristics. In this model, inner zone is modeled as a higher permeability radial reservoir because of the sand migration, while the outer zone is considered as a lower permeability reservoir. Besides, non-Newtonian fluid flow characteristics are considered as threshold pressure gradient in this paper. As a result, this bi-zone comprehensive model is built. The analytical solution to this composite model can be obtained using Laplace transformation, orthogonal transformation, and then the bottomhole pressure in real space can be solved by Stehfest and perturbation inversion techniques. Based on the oilfield cases validated in the oilfield data from the produced sand horizontal well, the flow regimes analysis shows seven flow regimes can be divided in this bi-zone model considering stress sensitive. In addition, the proposed new model is validated by the compassion results of traditional method without the complex factors. Besides, the effect related parameters of stress sensitivity coefficient, skin factor, permeability ratio and sanding radius on the typical curves of well-testing are analyzed. This work introduces two-zone composite model to reflect the variations of permeability caused by the produced sand in the unconsolidated sandstone formation, which can produce great influence on pressure transient behavior. Besides, this paper can also provide a more accurate reference for reservoir engineers in well test interpretation of loose sandstone reservoirs.

scholarly journals Effect of Matrix-Wellbore Flow and Porosity on Pressure Transient Response in Shale Formation Modeling by Dual Porosity and Dual Permeability System

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Daolun Li ◽  
Wenshu Zha ◽  
Dewen Zheng ◽  
Longjun Zhang ◽  
Detang Lu
Keyword(s):  
Transient Response ◽  
Shale Gas ◽  
Natural Fracture ◽  
Dual Porosity ◽  
Hydraulic Fractures ◽  
Pressure Transient ◽  
Adsorbed Gas ◽  
Shale Formation ◽  
Matrix Porosity ◽  
Wellbore Flow

A mathematical dual porosity and dual permeability numerical model based on perpendicular bisection (PEBI) grid is developed to describe gas flow behaviors in shale-gas reservoirs by incorporating slippage corrected permeability and adsorbed gas effect. Parametric studies are conducted for a horizontal well with multiple infinite conductivity hydraulic fractures in shale-gas reservoir to investigate effect of matrix-wellbore flow, natural fracture porosity, and matrix porosity. We find that the ratio of fracture permeability to matrix permeability approximately decides the bottom hole pressure (BHP) error caused by omitting the flow between matrix and wellbore and that the effect of matrix porosity on BHP is related to adsorption gas content. When adsorbed gas accounts for large proportion of the total gas storage in shale formation, matrix porosity only has a very small effect on BHP. Otherwise, it has obvious influence. This paper can help us understand the complex pressure transient response due to existence of the adsorbed gas and help petroleum engineers to interpret the field data better.

Pressure Transient Analysis for a Unique Shale Gas Condensate Well, Actual Field Case

2017 ◽  
Author(s):  
M. Ibrahim ◽  
C. Pieprzica ◽  
E. Vosburgh ◽  
A. Dabral ◽  
O. Olayinka ◽  
...  
Keyword(s):  
Shale Gas ◽  
Transient Analysis ◽  
Gas Condensate ◽  
Pressure Transient Analysis ◽  
Pressure Transient ◽  
Field Case ◽  
Actual Field

Diagnostic Plots of Pressure Transient, Rate-Transient, and Diagnostic Fracture-Injection/Falloff Tests

2021 ◽  
Author(s):  
David Craig ◽  
Thomas Blasingame
Keyword(s):  
Flow Regimes ◽  
Horizontal Stress ◽  
Test Theory ◽  
Pressure Transient ◽  
Diagnostic Plots ◽  
Diagnostic Plot ◽  
New Ideas ◽  
Characteristic Features ◽  
Pressure Transient Test ◽  
Minimum Horizontal Stress

Abstract All transient test interpretation methods rely on or utilize diagnostic plots for the identification of wellbore or fracture storage distortion, flow regimes, and other parameters (e.g., minimum horizontal stress). Although all "test" interpretations of interest are transient test data (i.e., those involving an "event"), the associated diagnostic plots are not interchangeable between such tests. The objective of this work is to clearly define the appropriate diagnostic plot(s) for each type of transient test. The work applies the appropriate transient test theory to demonstrate the applicability of each diagnostic plot along with clearly defining the characteristic features that make a given plot "diagnostic." For pressure transient testing, the material is largely a review, but for rate transient tests and diagnostic fracture-injection/falloff tests, new ideas are introduced and documented to justify appropriate diagnostic plots. Data examples are provided for illustration and application. In general, pressure transient test diagnostic plots are not misused, but the same cannot be said for diagnostic fracture-injection/falloff tests (or DFITs) where it is common to ascribe flow regimes and/or draw other erroneous conclusions based on observations from an inappropriately constructed or interpretated diagnostic plot. The examples provided illustrate both the correct diagnostic plot and interpretations, but also illustrate how data can be easily misinterpreted in common practice.

Sign in / Sign up

Export Citation Format

Share Document