Shuang Zheng

Aramco Services Company | ARAMCOSERVICES · Strategic Modeling Technology

In this paper, we present a novel fracture diagnostic method to determine the geometry of multiple propagating fractures. The method relies on the measurement of the Azimuthally Resolved WEllbore Strain Tensor (ARWEST) as a function of time at multiple locations in an observation well. A pad-scale fracturing simulator is used to simulate dynamic fr...

In the unconventional oil and gas domain, shale gas development adheres to the technical concept of "tight well spacing and infill well." Infill wells, along with large-scale hydraulic fracturing, have become effective strategies for increasing shale gas production. Nevertheless, during hydraulic fracturing operations in the horizontal wells, there...

Inflow Control Devices (ICDs) have been extensively used in injection wells to control the injection profile. The design of ICDs is usually based on the permeability and thickness of each injection zone. The primary objectives of this paper are to (a) study the influence of ICDs on the initiation and propagation of injection induced fractures (IIFs...

A new fiber optic measurement, Distributed Strain Sensing based on Rayleigh Frequency Shift, (DSS-RFS) was recently applied to wells in unconventional reservoirs. During production operations, strain changes are measured with high spatial resolution and sensitivity. The objective of this paper is to show that it is possible and very useful to simul...

The azimuthally resolved wellbore strain and geometry change provides a direct measure of the wellbore locations that are depleted due to production. As pore pressure decreases due to production, the stress field around borehole changes resulting in casing deformation which can be measured by field-scale downhole tools with high azimuthal resolutio...

In this paper we present an integrated DDM-based hydraulic fracturing-compositional reservoir simulator that can simulate each phase in the lifecycle of a hydraulically fractured well from hydraulic fracturing to shut-in, to flowback/production and gas huff-n-puff improved oil recovery. The new model is first bench marked against our in-house fully...

Multi-phase compositional wellbore flow is important in determining the flow and pressure drop in oil, gas, and geothermal wells. These effects become increasingly important in long laterals with multiple locations for fluid influx. Complex hydrocarbon phase behavior such as change in the number of phases, phase flipping, gas slippage can happen in...

Fracture diagnostic data for shale wells show that the fracture system after hydraulic fracturing is quite complex. Accurate and efficient simulation modeling of complex hydraulic and natural fracture networks is critical for evaluation of well performance and stimulation effectiveness in unconventional oil and gas reservoirs. The traditional metho...

This study presents a new workflow by integrating a robust 3D hydraulic fracture propagation model in conjunction with reservoir simulation through the embedded discrete fracture model (EDFM). Specifically, the hydraulic fracture model is applied to simulate more realistic fracture geometry considering 3D geomodel with rescue format and 3D natural...

Core data from the hydraulic fracturing test site 2 (HFTS-2) show that a complex fracture network is created. In this work, a novel fracturing-reservoir simulator is applied to the HFTS-2 data to provide a thorough assessment of the impact of the fracture network on well performance. A methodology is also presented to effectively represent the dyna...

A model for the flow of water and steam in a fractured geothermal reservoir is presented. The flow is coupled with thermal processes and phase behavior in the reservoir and fractures using the pressure-enthalpy formulation and water-steam phase behavior. Both an implicit pressure, explicit enthalpy and a fully implicit solution algorithm have been...

Several field cases have demonstrated polymer injection in a horizontal well increases oil recovery. It is important to maintain high injectivity while preventing injection-induced fractures to ensure good reservoir sweep. Our primary goal in this paper is to better understand polymer injection data from horizontal injectors in the Matzen field usi...

High breakdown pressure is one of the major challenges of deep and tight gas reservoirs. In certain wells, achieving breakdown pressures within the tubular completion yield limit is not possible. Such zones may have to be abandoned without fracturing. Using thermally controlled fluid can lower the formation temperature and ultimately reduce the str...

Reservoir cooling by water or wastewater injection can significantly change the stress in the target injection zones and the bounding layers. Out-of-zone fracture growth is substantially affected by these poro-thermo-elastic stress changes occurring in heterogeneous rock layers. No previous study has systematically investigated the influence of bot...

For simplicity, planar fractures are usually used for simulating well performance. This is clearly an oversimplification for naturally fractured formations. Core data from both HFTS 1 and 2 show that a much more complex fracture network is created. In this work, a novel three-dimensional fracturing-reservoir simulator is applied to the Hydraulic Fr...

The objective of this work is to investigate, develop, and demonstrate the direct link between wellbore casing strain / deformation measurements, and sealed well pressure responses. The paper presents new laboratory experiments for casing deformation that tie directly to wellbore deformation during hydraulic fracturing and to subsequent pressure in...

High breakdown pressure is one of the major challenges in deep tight gas reservoirs. In certain wells, achieving breakdown pressures within the completion tubular yield limit is not possible, and those zones may have to be abandoned without fracturing. Using thermally controlled fluid can lower the formation temperature and ultimately reduce the st...

Stranded gas emission from the field production because of the limitations in the pipeline infrastructure has become one of the major contributors to the greenhouse effects. How to handle the stranded gas is a troublesome problem under the background of global “net-zero” emission efforts. On the other hand, the cost of water for hydraulic fracturin...

Horizontal wells are often drilled and hydraulically fractured in tight reservoirs to produce hydrocarbons or heat. Different fracturing fluids such as slick water, gas, foam, gel, or a combination can be used with slick water being the most common fracturing fluid. In this paper, we study the impacts of different fracturing fluids on fractured wel...

Reservoir cooling during waterflooding or waste-water injection can significantly alter the reservoir stress field by thermo-poro-elastic effects. Colloidal particles in the injected water decrease the matrix permeability and buildup the injection pressure. Fractures may initiate and propagate from injectors. These fractures are of great concern fo...

Numerical modeling plays a key role in assessing, developing, and managing energy resources (such as oil, gas and heat) from subsurface formations. Fluids are injected into wellbores during hydraulic fracturing, water flooding, parent well pre-loading, and improved oil recovery. Oil, gas and water are produced back to the surface during flowback, p...

Lab experiments and numerical modeling have indicated that gas injection for IOR in tight oil reservoirs is technically feasible. Several operators have conducted pilots in the Eagleford and Bakken shales for a huff-n-puff IOR strategy with mixed results. Our objective in this work is to study the impact of (a) geomechanical effects during injectio...

In this paper, we present an integrated equation-of-state based compositional hydraulic fracturing and reservoir simulator. The goal of this research is to develop a general simulator that can simulate the lifecycle of wells, which includes hydraulic fracturing treatment using water-based or energized fracturing fluid, post-frac shut-in and flowbac...

In recent years, hydraulic fracturing design has evolved significantly. Fluid volumes injected in a lateral have more than doubled to ~ 250,000 bbl/well (Weijers et al., 2019). Increased injection volumes coupled with a sub-optimal completion design can lead to over-stimulation at current well spacing densities. In many instances, dominant clusters...

Hydraulic fracturing is a necessary process in order to produce oil and gas from tight reservoirs. Slick water is the most commonly used fracturing fluid whereas other fracturing fluids such as gel, gas, foam and hybrid fluids are much less common. In this paper, we evaluate the efficiency of different fracturing fluids on hydraulic fracturing by s...

Hydraulic fracturing has been widely used for producing oil and gas from tight reservoirs. During hydraulic fracturing, a large volume of fracturing fluid mixed with proppant are pumped downhole to create large propped fractures with high conductivity which greatly increases the contact area between the wellbore with the reservoir matrix. Proppant...

The primary objective of this work was to investigate the results and the possible mechanisms of oil recovery in a huff-n-puff style improved oil recovery (IOR) field pilot using nanoparticle assisted CO 2 injection. A secondary objective was to study the sensitivity of the process to injection volume of nanoparticles and gas, the type of injected...

Reservoir cooling by water or waste-water injection can significantly alter the reservoir stress. The out- of-zone fracture growth is substantially affected by this poro-thermo-elastic stress changes occurring in heterogeneous rock layers. No previous study, however, systematically investgated the influence of heat conduction and convection on the...

In shale oil reservoirs, cyclic CO2 injection has proven to be effective at recovering significant amounts of oil, however, certain downsides to the use of CO2 exist owing to its corrosive nature and its higher miscibility pressure compared to hydrocarbon gases such as ethane and propane. This paper presents simulation results focused on the impact...

This paper presents a fully integrated poro-thermo-elastic hydraulic fracturing and three-phase black-oil reservoir simulator. Both implicit-pressure-explicit-saturation and fully implicit solution algorithms are presented. The energy balance equation is solved in a coupled manner to calculate the temperature change caused by fluid injection for mu...

Due to gas pipeline infrastructure constraints, gas produced in many basins remains stranded. Innovative ways to utilize the produced gas are required. Additionally, the cost of frac-water is high in many areas. In this paper, we conduct a detailed technical feasibility study on using this excess natural gas (NG) as a fracturing fluid. Comparison i...

In shale oil reservoirs, cyclic CO 2 injection has proven to be effective at recovering significant amounts of oil, however, certain downsides to the use of CO 2 exist owing to its corrosive nature and its higher miscibility pressure compared to hydrocarbon gases such as ethane and propane. This paper presents simulation results focused on the impa...

Mitigating the negative impact of fracture hits on production from parent and child wells is challenging. This work shows the impact of parent-well depletion and repressurization on child-well fracture propagation and parent-well productivity. The goal of this study is to develop a method to better manage production/injection in the parent well so...

Fracture closure and proppant settling are two fully coupled processes during both shut-in and production. Proppant distribution greatly affects the residual fracture width and conductivity evolution, whereas fracture closure might limit proppant settling and force the proppant to crush or embed into the rock. Modeling fracture closure with proppan...

Peridynamics is a non-local theory of continuum mechanics that has been developed primarily for understanding material failure due to different mechanisms, including fluid-driven crack propagation during hydraulic fracturing of subsurface reservoirs. Because of its non-local nature, this theory is computationally expensive. To improve its performan...

This paper presents the formulation and results from a coupled finite-volume (FV)/finite-area (FA) model for simulating the propagation of multiple hydraulically driven fractures in two and three dimensions at the wellbore and pad scale. The proposed method captures realistic representations of local heterogeneities, layering, fracture turning, por...

Diagnostic fracture injection tests (DFITs) are often used to estimate formation properties such as closure stress, pore pressure, and matrix permeability. These estimations are typically based on analysis of pressure data assuming the closure of simple planar fractures in homogeneous reservoirs. These interpretations are incorrect when dealing wit...

Zipper fracturing is a method of sequencing frac jobs in multi-well pads that helps increase operational efficiency and reduce stimulation time for a pad. This technique involves stimulating several wells in a pad in a prescribed sequence of stages. In this work, we provide a thorough assessment of the various factors impacting the effectiveness of...

Mine-back experiments, lab experiments, and cores taken through fractured rock show that hydraulic fracturing treatments can create swarms of fractures. Subcritical crack growth, microcracking ahead of the fracture tip and failure of weak planes in the rock are mechanisms that have helped explain fracture swarming observed in both natural and hydra...

Mitigating the negative impact of frac-hits on production from parent and child wells is challenging. In this work, we show the impact of parent well depletion and repressurization on the child well fracture propagation and parent well productivity in different US shale reservoirs. By repressurizing the parent well, we do not imply repressurization...

During stimulation of unconventional reservoirs, offset well pressure measurements are often used to estimate hydraulic fracture geometry. These measurements can also be used to make a quantitative estimate of the created fracture network area and the permeability of the stimulated rock volume (SRV) around the hydraulic fractures. Offset well press...

During stimulation in a treatment well, offset well pressure measurements resulting from stress-shadow related interference are often used to estimate hydraulic fracture geometry. Current pressure interference models typically assume one dominant fracture per stage in their analysis, which is an overly simple assumption and can result in erroneous...

Simulating production from complex fracture networks is complicated due to different rates of closure of propped and unpropped fractures in a heterogenous time-varying stress field. Most of the existing models for simulating production from such hydraulic fractures do not consider geomechanics or use pressure as a proxy for changing the fracture co...

Diagnostic Fracture Injection Tests (DFIT) help to estimate various formation and fracture parameters such as closure stress, reservoir permeability, pore pressure, fracture compliance/stiffness and conductivity of un-propped fractures. All of the above require a precise depiction of the fracture closure process for accurate estimation of the vario...

Horizontal well fracturing is an established practice to improve the recovery of hydrocarbons from oil and gas reservoirs. To simulate fracture propagation, fracture closure during production and fracture reopening during fluid re-injection, it is essential to combine three important aspects of the problem: multiphase flow, geomechanics and fractur...

Numerical modelling of fracture propagation is challenging due to the highly non-linear dependence of the fracture conductivity which scales with the cube of fracture width. Most iterative methods that have been used to solve this coupled system are slow to converge and can easily diverge. Assumptions such as uniform fracture fluid pressure or homo...

Hydraulic fracture closure plays an important role during the shut-in period after a stimulation operation and during production from a reservoir. Fracture closure characteristics define the productivity of the created fractures. Fast fracture closure can prevent proppant from settling uniformly whereas gradual fracture closure can help in making t...

Field mine-back experiments and core-through experiments have shown that hydraulic fractures in the reservoir are often not planar. Complex growth of hydraulic fractures is evident in these field experiments. Microseismic data is often used to represent the complexity of created fractures in the formation. Numerical models that have been used to ca...

In conventional reservoirs, pressure communication between wells is ascribed to hydraulic diffusion through the rock matrix. In this work we show that in unconventional (low-permeability) reservoirs, pressure communication due to matrix diffusion is insignificant, and pressure changes observed in an offset monitor well during stimulation of a nearb...

Novel self-healing supramolecular hydrogels have successfully been fabricated through reversible cucurbit[8]uril (CB[8])-enhanced π-π interaction. Naphthaline groups in the side chains of copolymers and CB[8] molecules are employed as cross-linkers to form 1:2 ternary complex by host-guest interaction. Furthermore, the dipole-dipole interaction bet...