The downhole space of oil and gas wells is confined with complex temperature and pressure conditions. All chemical additives must meet multiple working requirements including long-distance transportation and long-term formation treatment. Thanks to unique slow-release performance, high safety and convenient operation brought by its special particle morphology, coarse-grained ammonium persulfate occupies an important position among oxidizing additives for petroleum exploitation. Fujian Zhanhua Chemical can adjust ammonium persulfate particle specifications on demand to match treatment processes of different oil blocks.

Ⅰ Morphology Advantages of Coarse-Grained Ammonium Persulfate for Petroleum Exploitation

(1) Controllable Slow Release to Meet Long-Term Downhole Treatment Requirements

The granular structure effectively slows down the dissolution process. After entering the formation, the additive will not react completely in an instant; oxidative active components are released slowly as particles dissolve gradually. Downhole operations usually require a certain residence period in the formation. The slowly released active oxygen can continuously act on various organic blockages throughout the target treatment cycle, avoiding insufficient formation treatment or reagent waste caused by short-term violent reactions.

(2) High Stability to Reduce Losses During Storage, Transportation and Construction

Regular granular morphology greatly suppresses powder dusting. A large amount of suspended dust will not be generated during material transfer and on-site liquid preparation, cutting unnecessary material loss and improving working environment. When stored in compliance with MSDS standards, the material resists moisture absorption and caking during stacking, maintaining stable reaction activity even after long-term storage. Relying on a standardized production system to control particle uniformity, Fujian Zhanhua Chemical effectively guarantees stable material status throughout warehousing and transportation.

(3) Reasonable Dissolution Gradient Matching Pore Characteristics of Oil Layers

Coarse-grained ammonium persulfate dissolves layer by layer in formation fluids, forming an active oxygen concentration gradient: high concentration near the wellbore and continuous replenishment deep in the formation along seepage paths, which continuously degrades polymer filter cakes and organic colloids accumulated in pores.

For pore channels of varying widths inside oil reservoirs, this gradient release mode facilitates layered removal of organic residues and helps restore fluid flow capacity of formations. Capsule-type products realize delayed release triggered by temperature or pressure through polymer shells (active components released only after reaching target formations). The gradient dissolution of coarse grains relies on physical morphology to achieve slow release. The two methods differ in implementation routes and cost significantly. Customers can make comprehensive selections based on downhole temperature, construction cycle and budget.

(4) Superior Safety Adaptable to Complex Downhole Working Conditions

Fine powder features large specific surface area, leading to short induction period and high initial reaction rate when contacting metal debris or organic impurities inside wellbores. Coarse grain morphology lowers the initial contact reaction rate and mitigates risks of violent reactions during liquid preparation and injection. Meanwhile, the granular structure weakens instantaneous oxygen release, fully meeting safety control requirements for slow oxygen release of oxidants in confined downhole spaces.

Ⅱ Core Application Scenarios of Coarse-Grained Ammonium Persulfate in Petroleum Exploitation

(1) Fracturing Fluid Gel Breaking to Keep Oil and Gas Flow Channels Unobstructed

Polymer gel systems injected during hydraulic fracturing carry proppants to fill formation fractures. If residual gel remains inside fractures after construction, it will block oil and gas seepage paths. Transported deep into formations with fracturing fluid, coarse-grained ammonium persulfate dissolves gradually and releases oxidative active substances to break molecular chains of polymer gels, converting high-viscosity gel into low-viscosity fluid for smooth flowback, and fully preserving seepage channels formed by artificial fractures.

(2) Reservoir Plug Removal & Injection Enhancement to Activate Low-Efficiency Oil Reservoirs

Long-term exploited oil layers often accumulate polymer residues, biological mucilage and heavy colloids, forming composite organic blockages that narrow formation pores and continuously reduce oil-gas production and water injection efficiency. Oxidative media released slowly by granular ammonium persulfate decompose various organic blockages layer by layer, unclog blocked pores, restore original reservoir seepage capacity and improve operation performance of injection and production wells.

(3) Oilfield Wastewater Purification & Removal of Organic Deposits in Pipelines

Produced oilfield wastewater contains crude oil, residual polymer additives and microbial metabolites, which will form organic sediment layers on inner pipeline walls after long-term transportation. Mixed into water treatment systems, coarse-grained ammonium persulfate releases active oxygen slowly to degrade refractory organic pollutants in wastewater and oxidatively strip organic deposits attached to pipeline inner walls. It realizes both wastewater purification and pipeline maintenance, lowering pipeline cleaning frequency.

(4) Special Treatment for Medium & Low Temperature Oil Reservoirs

Formations of shallow and high-latitude oil blocks mostly stay within medium-low temperature ranges, where ammonium persulfate carries high activation energy for decomposition. Coarse grain morphology extends the physical dissolution cycle, allowing undissolved ammonium persulfate to persist in formation fluids and prolong the effective reaction window. It extends oxidation duration under low-temperature environments and improves overall degradation performance.

Reminder on Application Limits: Under extremely low temperature conditions, ammonium persulfate decomposes extremely slowly even in coarse-grained form. It is recommended to use redox activators (ferrous sulfate, organic amines, etc.) for synergistic treatment. Activators reduce decomposition activation energy and further boost gel breaking and plug removal efficiency at low temperatures.

With multiple advantages including slow release, high stability and superior safety brought by granular morphology, coarse-grained ammonium persulfate covers various downhole operations such as fracturing gel breaking, reservoir plug removal, wastewater treatment and medium-low temperature reservoir remediation. Its differentiated physicochemical properties derived from particle morphology deliver unique application value among oxidizing additives for petroleum exploitation. For years, Fujian Zhanhua Chemical has continuously upgraded production processes for coarse-grained ammonium persulfate to meet diversified formation treatment demands of oilfields, providing highly compatible raw materials for oil and gas development operations.

Important Notice

Ammonium persulfate is Class 5.1 oxidizing dangerous goods with UN No. 1444 and Packing Group III. Storage requirements: Store in dry, cool and well-ventilated areas, strictly isolated from combustibles, reducing agents, acids, metal powders and amine compounds. All transportation and downhole liquid preparation operations must comply with relevant specifications. Operators shall be fully equipped with protective gear including acid-resistant gloves, safety goggles and dust masks. For product COA test reports and SDS safety data sheets, please contact our technical department for application.