Study on Acidizing Effect of Cationic β-Cyclodextrin Inclusion Complex with Sandstone for Enhancing Oil Recovery

Zou, Changjun; Qin, Yibie; Yan, Xueling; Zhou, Lu; Luo, Peng

doi:10.1021/ie501569d

Cited by 16 publications

(12 citation statements)

References 45 publications

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“…As can be seen in Figure 2a, the characteristic absorption peaks of piperazine at 3208 and 1553 cm −1 correspond to the stretching and bending vibration of the -NH-groups, respectively, and the one at 1328 cm −1 is ascribed to the stretching vibration of the C-N bond [30]. With respect to the FTIR spectrum of HP, the characteristic absorption peaks of HEDP are observed at 3268 cm −1 (-OH, stretching vibration), 3010 (-CH 3 , stretching vibration), 1135 (-P=O, stretching vibration), 1031 (P-O, stretching vibration), and 526 cm −1 (P-O, bending vibration) [31,32]. Notably, the disappearance of -NH-and the formation of a new peak of -NH 3 + at 1451 cm −1 indicate that piperazine reacted with HEDP completely.…”

Section: Characterization Of Hp and Hp-mnmentioning

confidence: 99%

Preparation of Mn2+ Doped Piperazine Phosphate as a Char-Forming Agent for Improving the Fire Safety of Polypropylene/Ammonium Polyphosphate Composites

2021

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A piperazine phosphate doped with Mn2+ (HP-Mn), as a new char-forming agent for intumescent flame retardant systems (IFR), was designed and synthesized using 1-hydroxy ethylidene-1,1-diphosphonic acid, piperazine, and manganese acetate tetrahydrate as raw materials. The effect of HP-Mn and ammonium polyphosphate (APP) on the fire safety and thermal stability of polypropylene (PP) was investigated. The results showed that the combined incorporation of 25 wt.% APP/HP-Mn at a ratio of 1:1 endowed the flame retardant PP (PP6) composite with the limiting oxygen index (LOI) of 30.7% and UL-94 V-0 rating. In comparison with the pure PP, the peak heat release rate (PHRR), the total heat release (THR), and the smoke production rate (PSPR) of the PP6 were reduced by 74%, 30%, and 70%, respectively. SEM and Raman analysis of the char residues demonstrated that the Mn2+ displayed a catalytic cross-linking charring ability to form a continuous and compact carbon layer with a high degree of graphitization, which can effectively improve the flame retardancy of PP/APP composites. A possible flame-retardant mechanism was proposed to reveal the synergistic effect between APP and HP-Mn.

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Section: Characterization Of Hp and Hp-mnmentioning

confidence: 99%

Preparation of Mn2+ Doped Piperazine Phosphate as a Char-Forming Agent for Improving the Fire Safety of Polypropylene/Ammonium Polyphosphate Composites

2021

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“…Formation acidizing and hydraulic fracturing are both two common solutions to mitigate the formation damage problem. The hydraulic fracturing process aims to bypass the damaged zone around the wellbore by creating a high permeability path within the reservoir that is connected to the well. − On the other hand, acidizing treatment aims generally to enhance the well productivity by either dissolving the formation rock itself or removing the well-induced damage. − Acid treatment was initially used to stimulate carbonate reservoirs by dissolving the rock matrix . However, with the industry development, special types of acid were evolved to treat sandstone reservoir damage that occurs during drilling, completion, enhanced oil recovery, or even production period. , …”

Section: Introductionmentioning

confidence: 99%

Novel Approach for Sandstone Acidizing Using in Situ-Generated Hydrofluoric Acid with the Aid of Thermochemicals

2020

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In this study, an in situ-generated hydrofluoric acid (HF) was used for sandstone acidizing, where an acid precursor (ammonium fluoride NH 4 F) reacted with a suitable oxidizer (sodium bromates NaBrO 3 ) in an exothermic reaction. First, the new chemical mixture was prepared to react with pure quartz samples and the reaction effluent was analyzed to identify the presence of Si + ions using the inductively coupled plasma (ICP) technique. Core flooding experiments were performed using Gray Berea sandstone cores (6 in. length and 1.5 in. diameter). A preflush stage of 5 PV of 7 wt % HCl was injected to remove any calcite content in the core. The main chemicals were then flushed for 3 successive cycles of 1 PV each. To assure core integrity, scratch tests and NMR scans were run on the core sample before and after the treatment. The new chemical mixture could dissolve the quartz sample and reduce its weight by 80 mg. The concentration of the dissolved Si + ions was more than 90 ppm. This proves the capability of the chemical mixture to generate HF. The initial core permeability was measured at a stabilized flow rate of 2 cm 3 /min to be 33 mD. After the acid preflush stage, the core permeability reduced to 31 mD. Core permeability increased immediately after the first treatment cycle and reached 41 mD. At the end, the core flooding results showed a permeability improvement for Gray Berea sandstone cores by almost 40%. The ICP analysis of the effluent showed a total amount of chelated Si + ions of about 10.5 mg. In addition to the high temperature generated in the near-wellbore area, the pressure increased because of the produced nitrogen gas from the exothermic reaction and reached about 600 psi. The scratch test showed an increase in the sample uniaxial compressive strength from 7432 to 9235 psi. The dynamic Poisson's ratio and the dynamic Young's modulus increased as well from 0.17 to 0.19 and from 2159 to 3585 ksi, respectively. The enhancement in the mechanical properties of the core can be attributed to the presence of the potassium element in Berea cores and its solidification reaction with the HF generated. The NMR measurements of the core sample before and after the acidizing process show an increase in the core porosity; however, the core preserved its original pore system. Upon application of this new stimulation technology, the true production potential of sandstone reservoirs can be achieved, well tubular corrosion will be minimized, and handling hazardous chemicals such as HF will be avoided. Most importantly, controlling the reaction rate, by controlling the amount of exothermic chemicals, can ensure deep acid penetration as well.

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“…Retarded acids (such as gel, emulsion, autogenous, organic, cross-linked, and foam acids) can slow down the consumption rate of the acid and improve its EPD , but may also affect the acid efficiency or increase the cost of additives. However, improving the acid EPD by increasing the displacement will increase the difficulty of acid fracturing, provide uncontrollable variation of the fracture height, and cause other problems. − Also, the reaction rate of acid rocks increases rapidly with temperature and the development of high-temperature oil and gas reservoirs puts forward higher requirements for the acid retardation performance . Therefore, it is necessary to develop an acid with excellent retarding performance and high effective H + concentration.…”

Section: Introductionmentioning

confidence: 99%

Innovative Encapsulating Acid with Release Dually Controlled by the Concentration of Hydrogen Ions and Temperature

et al. 2019

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Acid fracturing is a stimulation method in carbonates, in which the acid is injected into a hydraulically created fracture. The encapsulating/coating acid proposed in this paper can realize deep penetrating acid fracturing, increase the effective action distance of acid solution, and improve the flow conductivity at the far end of fractures. For this purpose, a solid acid encapsulating/coating material is proposed, which maintains its structural integrity and isolates the solid acid at higher H+ ion concentrations and lower temperatures. The solid acid is released at lower H+ concentrations and higher temperatures due to the fracture of the encapsulating material. Thus, the acid release process is dually controlled by the concentration of hydrogen ions and temperature. The molecular structure, characteristic viscosity, and solubility of the encapsulating material were experimentally determined, as well as the effective content, release performance, corrosion performance, and dissolution performance. The encapsulating material was found to be composed of acrylamide and other polymers, belonging to the high polymer group. Its characteristic viscosity was approximately 2.445 dL/g, making it mainly insoluble in a high-concentration acid (>16%). The effective content of the encapsulating acid reached 85%, the critical release concentration of hydrochloric acid was about 14%, and the critical release temperature was about 95 °C (for hydrochloric acid concentration not exceeding 14%). Its corrosion performance was somewhat better than that of hydrochloric acid of the same concentration. The encapsulating/coating acid proposed in this paper has promising application prospects in the acid fracturing reconstruction of high-temperature deep carbonate reservoirs.

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Study on Acidizing Effect of Cationic β-Cyclodextrin Inclusion Complex with Sandstone for Enhancing Oil Recovery

Cited by 16 publications

References 45 publications

Preparation of Mn2+ Doped Piperazine Phosphate as a Char-Forming Agent for Improving the Fire Safety of Polypropylene/Ammonium Polyphosphate Composites

Preparation of Mn2+ Doped Piperazine Phosphate as a Char-Forming Agent for Improving the Fire Safety of Polypropylene/Ammonium Polyphosphate Composites

Novel Approach for Sandstone Acidizing Using in Situ-Generated Hydrofluoric Acid with the Aid of Thermochemicals

Innovative Encapsulating Acid with Release Dually Controlled by the Concentration of Hydrogen Ions and Temperature

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