Unconventional Shale Gas-Condensate Reservoir Performance Impact of Rock, Fluid and Rock-Fluid Properties and Their Variations

Orangi, Abdollah; Nagarajan, Narayana Rao; Rosenzweig, J.J.

doi:10.15530/urtec-2015-2170061

Cited by 4 publications

(3 citation statements)

References 19 publications

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“…This production model is designed to simulate the application of inverted five-spot gas cycling in the reservoir and perform sensitivity studies on different drainage strategies. Assigning LGR near production wells could yield slightly better simulation results, however, with increasing number of grid blocks the computation time increases resulting in more storage occupancy and delays simulation results [15]. Thus for this model, this small grid size with these number of grid blocks (mentioned above) have been selected to perform the simulation.…”

Section: Reservoir Model Descriptionmentioning

confidence: 99%

Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

Shams

Zhang

et al. 2017

Open Physics

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Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulationcondensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources. In gas injection, the flooding pattern, injection timing and injection duration are key parameters to study an efficient EOR scenario in order to recover lost condensate. This work contains sensitivity analysis on different parameters to generate an accurate investigation about the effects on performance of different injection scenarios in homogeneous gas condensate system. In this paper, starting time of gas cycling and injection period are the parameters used to influence condensate recovery of a five-spot well pattern which has an injection pressure constraint of 3000 psi and production wells are constraint at 500 psi min. BHP. Starting injection times of 1 month, 4 months and 9 months after natural depletion areapplied in the first study. The second study is conducted by varying injection duration. Three durations are selected: 100 days, 400 days and 900 days. In miscible gas injection, miscibility and vaporization of condensate by injected gas is more efficient mechanism for condensate recovery. From this study, it is proven that the application of gas cycling on five-spot well pattern greatly enhances condensate recovery preventing financial, economic and resource loss that previously occurred.

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Section: Reservoir Model Descriptionmentioning

confidence: 99%

Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

Shams

Zhang

et al. 2017

Open Physics

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“…9 The impairment to condensate recovery is more severe in shale reservoirs than in conventional reservoirs. 24 In the nanopores of shale reservoirs, the reservoir fluid transport properties and phase behavior are altered, which are affected by the capillary pressure and increased molecule−pore wall interactions. Wang et al 39 presented one of the first experimental observations of the altered phase behavior of an alkane and a ternary alkane mixture under nanoconfinement using nanofluidic devices.…”

Section: Introductionmentioning

confidence: 99%

“…Condensate build-up in the hydraulic fractures and surrounding formation matrix reduces the fracture conductivity and relative permeability to gas, causing a decline in the efficiency and productivity of the well . The impairment to condensate recovery is more severe in shale reservoirs than in conventional reservoirs …”

Section: Introductionmentioning

confidence: 99%

A Comparative Experimental Study of Huff-n-Puff Gas Injection and Surfactant Treatment in Shale Gas-Condensate Cores

2018

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Experimental and simulation studies have thus far demonstrated that gas injection is an effective way of recovering condensate in shale gas-condensate reservoirs. It is economically feasible and relatively easier to be injected into the tight reservoir as compared to most of the other injection fluids. To the best of our knowledge, surfactant treatment has not been tested in shale cores for gas-condensate fluid systems. In this study, the experimental performances of huff-n-puff gas injection and surfactant treatment are compared in recovering condensate from shale cores. A nonionic fluorocarbon surfactant is screened for experiments based on dynamic contact angle measurements for suitable use in core flooding experiments. The principle of fluorocarbon surfactants is to alter the core from liquid wetting to favorably gas-wetting condition, thus reducing the average condensate saturation trapped in the core. First, an ideal experiment is used to set up two-phase gas and oil flow similar to a gas-condensate reservoir. In this ideal experiment, methane is flooded through surfactant treated and untreated shale cores, which are both initially saturated with n-decane. The oil saturation thus established was reduced by 28% in the surfactant treated core, as compared to the untreated core. On the basis of the success of surfactant treatment in the ideal experiment, we designed realistic experiments for a gas-condensate system in a shale core. In these experiments, the shale core is flooded with a gas-condensate mixture to mimic the dynamic flow of gas-condensate fluid in the reservoir. The performance of surfactant treatment is compared with huff-n-puff gas injection to recover accumulated condensate from different zones mimicking those in the reservoir ranging from high condensate build-up zones (fracture and near fracture regions) to low condensate build-up zones (matrix) occurring further into the reservoir. Results indicate that wettability alteration of the core achieved due to surfactant treatment is capable of enhancing recovery only from the zones where the developed condensate saturation high. A large volume of treatment solution is required for the wettability alteration to be effective in the shale cores, but it is difficult because the penetration is shallow. Also, the effectiveness of injected surfactant is not found to be long lasting. This could considerably increase the cost of surfactant application in the field if frequent treatments are required. The main problem of surfactant treatment is observed to be the difficulty of injection and flowback of treatment solution in the tight shale cores and thus limits its application to the high permeability fracture network of a reservoir. However, a large pore volume of the reservoir consists of ultralow permeability nanopores, which will have a considerable volume of trapped condensate as the reservoir pressure is depleted. In comparison, huff-n-puff gas injection proved to be more efficient in terms of higher recovery in all of the studied zones, relatively ea...

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Capillary-condensation hysteresis in naturally-occurring nanoporous media

Barsotti

Piri

Chen

2020

Fuel

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Unconventional Shale Gas-Condensate Reservoir Performance Impact of Rock, Fluid and Rock-Fluid Properties and Their Variations

Cited by 4 publications

References 19 publications

Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

A Comparative Experimental Study of Huff-n-Puff Gas Injection and Surfactant Treatment in Shale Gas-Condensate Cores

Capillary-condensation hysteresis in naturally-occurring nanoporous media

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