Optimisation of Well and Layer Selection for Re-fracturing

2021 ◽  
Author(s):  
Qi Zhu
Keyword(s):  
Oil And Gas ◽  
Evaluation Model ◽  
Machine Intelligence ◽  
Parameter Method ◽  
Gas Reservoirs ◽  
Fracture Conductivity ◽  
Oil Distribution ◽  
Well Pattern ◽  
Elasto Plasticity ◽  
Single Well

Abstract In initial fracturing of tight oil and gas reservoirs, due to the influence of geological and technological factors, the fracture conductivity has decreased, and the single-well productivity has been reduced. It is urgent to repeat transformation to restore or increase productivity. Well selection and layer selection is one of the key factors that affect the design of re-fracturing and the effect of stimulation. Based on a big database of well-sites, establishing machine intelligence theory determines the elasto-plasticity, permeability, porosity, completion parameters, production decline parameters and skin coefficient that affect the effect of re-fracturing stimulation by dimensionless parameter method of well and layer selection and its stimulation evaluation model. Combined with artificial neural network and BP algorithm, the index weights of strata with different reservoir physical properties are calculated to analyze the final evaluation value of fracturing effect. On the basis of remaining oil distribution research, scale extended fracture repeated fracturing is increased, injection-production well pattern is improved, scale repeated fracturing effect is increased, well pattern is improved, target layer is repeatedly fractured, and oil increase effect is obvious after fracturing.

Experimental Study on the Saturation Model of Volcanic Rock Based on Fluid Distribution

2021 ◽  
Vol 62 (4) ◽  
pp. 422-433
Author(s):  
Baozhi Pan ◽  
◽  
Weiyi Zhou ◽  
Yuhang Guo ◽  
Zhaowei Si ◽  
...  
Keyword(s):  
Volcanic Rock ◽  
Oil And Gas ◽  
Water Saturation ◽  
Early Stage ◽  
Evaluation Model ◽  
Acoustic Velocity ◽  
Distribution Model ◽  
Fluid Distribution ◽  
Water Drainage ◽  
Gas Reservoirs

A saturation evaluation model suitable for Nanpu volcanic rock formation is established based on the experiment of acoustic velocity changing with saturation during the water drainage process of volcanic rock in the Nanpu area. The experimental data show that in the early stage of water drainage, the fluid distribution in the pores of rock samples satisfies the patchy formula. With the decrease of the sample saturation, the fluid distribution in the pores is more similar to the uniform fluid distribution model. In this paper, combined with the Gassmann-Brie and patchy formula, the calculation equation of Gassmann-Brie-Patchy (G-B-P) saturation is established, and the effect of contact softening is considered. The model can be used to calculate water saturation based on acoustic velocity, which provides a new idea for the quantitative evaluation of volcanic oil and gas reservoirs using seismic and acoustic logging data.

Research Progress in Calculation Methods for Single-Well Dynamic Reserves of Gas Reservoirs

2014 ◽  
Vol 1044-1045 ◽  
pp. 401-405
Author(s):  
Hai Dong Shi
Keyword(s):  
High Efficiency ◽  
Research Progress ◽  
Calculation Methods ◽  
Gas Wells ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Well Spacing ◽  
Well Pattern ◽  
Single Well ◽  
Gas Fields

Dynamic reserves are the important basis for determining the reasonable deliverability of gas wells and well spacing density and also the foundation for the overall development plan of a gas field. Therefore, the evaluation of dynamic reserves of gas wells is crucially important to developing gas fields with high efficiency, optimizing well pattern and shortening development period. For this reason, this paper arranges and analyzes systematically a series of calculation methods for dynamic reserves of single gas well, which have arisen in recent years, and identifies the calculation methods for different types of gas reservoirs.

Spatial Distribution of Thin Interbeds in Point Bars of Meadering Channels: Case Study of Block X in Daqing Oilfield

2012 ◽  
Vol 524-527 ◽  
pp. 199-204
Author(s):  
Bai Quan Yan ◽  
Xiao Lei Tian ◽  
Hong Qing Kang ◽  
Long Wang
Keyword(s):  
Oil And Gas ◽  
Outer Boundary ◽  
Structural Features ◽  
Gas Reservoirs ◽  
Oil Accumulation ◽  
Meandering Channels ◽  
Oil Distribution ◽  
Remaining Oil ◽  
Point Bars ◽  
Abandoned Channels

Reservoirs in point bars of meandering channels account for a high proportion in oil and gas reservoirs, with much impact of complicated architecture on remaining oil accumulation and distribution. Thus study on inner architecture of point bars and its impact on remaining oil distribution are important. This paper selects Unit III in Block A in Daqing Oilfield with data in filled well patterns and cores to study inner architecture of subsurface single sand bodies, and analyzes 3D structural features of meandering point bars in Xingbei deltaic plain in Daqing Placanticline. Architecture parameters of lateral accretion shale interbeds are: eastward dip averagely 7°, the upper, middle and lower dip in same accretion face are respectively 10°, 7° and 3°, the width is 15-42m. They are vertically imbricated series and areally corner points of abandoned channels on both sides of meandering rings as track collection intersections, and progressive and curvature reducing arc sets with abandoned channels of meandering rings as outer boundary. This pattern provides geologic basis for successive study on remaining oil.

scholarly journals Assessing the effect of proppant compressibility on the conductivity of heterogeneously propped hydraulic fracture

2021 ◽  
Vol 2057 (1) ◽  
pp. 012078
Author(s):  
A M Skopintsev
Keyword(s):  
Hydraulic Fracture ◽  
Oil And Gas ◽  
Production Performance ◽  
Fracture Aperture ◽  
Strong Impact ◽  
Gas Reservoirs ◽  
Fracture Conductivity ◽  
Fracture Closure ◽  
Oil And Gas Reservoirs ◽  
Treatment Design

Abstract Hydraulic fracturing is a technology that is widely used in the development of oil and gas formations. Given that the fracture closure has a strong impact on production, quantifying the resulting fracture conductivity is critical for optimizing treatment design. The goal of this paper is to better understand the influence of the closing stress on the fracture conductivity when the proppant distribution is heterogeneous. In addition to the spatial proppant distribution, the conductivity of the propped fracture is affected by proppant deformation and embedment. Numerical results indicate that compressibility of proppant can significantly change the residual fracture aperture and, consequently, production performance in oil and gas reservoirs

Production Performance Evaluation of Multifractured Horizontal Wells in Shale Oil Reservoirs: An Analytical Method

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Xingbang Meng ◽  
Jiexiang Wang
Keyword(s):  
Production Rate ◽  
Analytical Method ◽  
Oil And Gas ◽  
Production Performance ◽  
Single Fracture ◽  
Shale Oil ◽  
Affecting Factors ◽  
Gas Reservoirs ◽  
Fracture Conductivity ◽  
Fracture Spacing

Hydraulic fracturing stimulation has become a routine for the development of shale oil and gas reservoirs, which creates large volumes of fracturing networks by helping the hydrocarbon to transport quickly into the wellbore. However, the optimal fracture spacing distance and fracture conductivity are still unclear for the field practice, even though the technique has improved significantly over the last several years. In this work, an analytical method is proposed to address it. First, the analytical production rate for a single fracture is proposed, and then, we apply Duhamel principle to obtain the production rate of a horizontal well with multifractures. Based on this model, the flow regimes and essential affecting factors including fracture spacing, fracture conductivity, and skin factor are analyzed in this work. The optimal values and suggestion are provided based on the simulation results.

scholarly journals Relationship between well pattern density and variation function of stochastic modelling and database establishment

2020 ◽  
Vol 75 ◽  
pp. 84
Author(s):  
Jinkai Wang ◽  
Kai Zhao ◽  
Zhaoxun Yan ◽  
Yuxiang Fu ◽  
Jun Xie
Keyword(s):  
Oil And Gas ◽  
Stochastic Modelling ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Pattern Density ◽  
Vertical Range ◽  
Variation Function ◽  
Well Pattern ◽  
Geological Conditions ◽  
Degree Of Convergence

For 3D geological modelling of oil and gas reservoirs, well pattern density is directly related to the number of samples involved in the calculation, which determines the variation function of stochastic modelling and has great impacts on the results of reservoir modelling. This paper focuses on the relationship between well pattern density and the variogram of stochastic modelling, selects the large Sulige gas field with many well pattern types as the research object, and establishes a variogram database of stochastic models for different well pattern densities. First, the well pattern in the study area is divided into three different types (well patterns A, B, and C) according to well and row space. Several different small blocks (model samples) are selected from each type of well pattern to establish the model, and their reasonable variogram values (major range, minor range and vertical range) are obtained. Then, the variogram values of all model samples with similar well pattern densities are analysed and counted, and the variogram database corresponding to each type of well pattern is established. Finally, the statistical results are applied to the modelling process of other blocks with similar well pattern density to test their accuracy. The results show that the reservoir model established by using the variation function provided in this paper agrees well with the actual geological conditions and that the random model has a high degree of convergence. This database has high adaptability, and the model established is reliable.

Restoring Erroneous or Missing Rates in Interfering Wells Using Multiwell Deconvolution

2021 ◽  
Author(s):  
Kambiz Razminia ◽  
Alain C. Gringarten
Keyword(s):  
Oil And Gas ◽  
Well Test ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Flow Rates ◽  
Deconvolution Algorithm ◽  
Oil And Gas Field ◽  
Single Well ◽  
Actual Flow ◽  
True Flow

Abstract Objectives/Scope Single well deconvolution (von Schroeter et al., 2001) has been added to the well test interpretation toolbox nearly twenty years ago. In recent years, the single well deconvolution algorithm has been extended to multiple interfering wells (Cumming et al., 2013), and further improved with the additions of constraints to account for existing a-priory knowledge on the reservoir (constrained multiwell deconvolution, Cumming et al., 2019). The main objective of multiwell deconvolution is to identify the signatures of all wells involved and the interference signals between wells, from which information can be extracted about the reservoir that may not be obtainable otherwise, e.g. heterogeneities, boundaries and compartmentalization. The single well deconvolution algorithm has also been shown to be capable of restoring erroneous or missing rates (Gringarten, 2010). As shown in this paper, the same is true with multiwell deconvolution, which is able to restore erroneous or missing rates in all the wells involved. Methods, Procedures, Process Starting with arbitrary initial guesses for the missing rates in the various wells involved, we use multiwell deconvolution to estimate these missing flow rates or correct for erroneous ones. Two methods are presented: (1) we use unconstrained multiwell deconvolution as a first step to estimate the missing/erroneous rates, then use constrained multiwell deconvolution with these rates to estimate deconvolved derivatives; and (2) we restore/correct the flow rates and derive deconvolved derivatives simultaneously using constrained multiwell deconvolution. We show that the first approach is more accurate than the second one. In both approaches, we only obtain rates that are proportional to the true flow rates. To obtain the true flow rates, we need to know either one of the actual flow rates in each well, or the corresponding permeabilities. Results, Observations, Conclusions We prove the ability of multiwell deconvolution to estimate rates on synthetic oil reservoirs and gas reservoirs with moderate average reservoir pressure depletion, that include non-interfering wells. We then apply to oil and gas field examples and compare restored vs. actually measured rates. In all cases, the agreement is very good. Novel/Additive Information Using only measured pressure data, constrained multiwell deconvolution can be used to restore unknown flow rates and/or correct for erroneous rates, in addition to estimating deconvolved derivatives of all wells. This is particularly useful in the case of allocated rates or when rates are missing in some of the interfering wells.

scholarly journals Fuzzy Comprehensive Evaluation on the Effect of Measures Operation for Oil-Water Well

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Zhi-Bin Liu ◽  
Wei Qing ◽  
Xin-Hai Kong
Keyword(s):  
Oil And Gas ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Gas Production ◽  
Oil Field ◽  
Oil And Gas Production ◽  
Evaluation Approach ◽  
Quantitative Calculation ◽  
Single Well

The measures operation is an important component of borehole operation, and the operation effects directly affect the increase of oil and gas production. In perspective of the present reality of borehole operation company, the authors analyze the commonly used type of measures on the oil field, summarize six indicators to evaluate the measures operation effect, and give the quantitative calculation method for six evaluation indicators. Through the experts grading method, we can obtain all the weights of indicators and then establish the fuzzy comprehensive evaluation model of operation effect of measures. The evaluation model can be used to evaluate the operation effect of single well, oil block, or the branch company. Based on the actual data of measures operation of a branch company, using the fuzzy comprehensive evaluation approach to evaluate each block in the branch company, this paper obtained the same conclusion as the qualitative analysis.

Sign in / Sign up

Export Citation Format

Share Document