How to deal with fracturing flowback fluid in the Jiaoshiba block of Fuling shale gas production dem

In 2013, He Huanjie, deputy chief engineer of the Drilling Engineering Technology Research Institute and director of the Environmental Protection Research Institute of Zhongyuan Petroleum Engineering Company, led the scientific researchers to tackle key problems such as strict control of the introduction of foreign interference ions, retention of active ingredients, and removal of harmful components with the goal of wastewater reuse. After more than two years of hard work, their independent research and development of shale gas fracturing flowback fluid composite coagulation-filtration-adsorption purification treatment and liquid preparation process not only saves fresh water resources, but also eliminates the adverse impact of fracturing on the surrounding ecological environment, and realizes the green, environmentally friendly, safe and efficient development of shale gas. Finally, the fracturing flowback fluid reuse purification process, composite coagulation treatment process, fracturing flowback fluid adsorption advanced treatment process and other technologies are formed.

Fracturing flowback fluid is usually treated in the following ways:

1. Oil separator pretreatment.

2. Coagulation air flotation polyaluminum chloride + reversed-phase demulsifier + anionic polyacrylamide + air flotation machine.

3. Chemical treatment method.

4. Adsorption method.

5. Biochemical treatment method.

At present, in the process of oilfield exploitation, in the face of the problem of hydraulic fracturing using a large amount of water resources and serious pollution of fracturing flowback fluid, the reuse of flowback fluid is the future trend of oil and gas field industry development from both cost and environmental protection considerations.

With the rapid development of oilfield chemicals, the construction situation on site has higher and higher requirements for fracturing fluid, and the chelating agent type of corrosion and scale inhibition fracturing fluid is more in line with the comprehensive development needs of oilfield additives in the future.

In the process of re-use of the flowback treatment solution, because the reverse discharge solution contains a large number of divalent ions such as Ca2+, Mg2+, Fe2+, etc

1. It has a great impact on the stickiness and temperature resistance of the thickener.

2. Because the large amount of calcium, magnesium ions, carbonate and sulfate ions contained in the reverse drainage treatment solution are easy to scale and precipitate at a certain concentration and temperature, when the fracturing fluid made of reverse drainage fluid is directly injected into the underground process again, it is easy to scale and block the diversion channel of the supporting fractures, which greatly reduces the effect of fracturing stimulation and causes production reduction or even production shutdown.

In view of the above problems, our company, together with Southwest Petroleum University, China University of Petroleum, Xi'an Shiyou University and other institutions, has developed chelating additives applied to different villain treatment fluid environments and different fracturing fluid formulations in view of the complex situation of different reverse drainage treatment fluids in Changqing Oilfield, Daqing Oilfield, Southwest Oil and Gas Field, Karamay Oilfield and other oilfield blocks in China, after years of in-depth analysis, experimental simulation and field application, which not only effectively reduces Ca2+, Mg2+ and Fe2+ in the reverse drainage fluidThe influence of plasma on the viscosity and temperature resistance of fracturing fluid, and solves the problem of corrosion and scaling of the reinjection channel, especially the QH-7510 product developed by our company 990396, which has been evaluated by many oilfield units of oil and gas institutes, and has achieved the excellent effect of scale inhibition rate: calcium carbonate 95%, calcium sulfate 95%, and barium sulfate 95%, which can save the secondary addition of water reinjection and corrosion inhibitors and scale inhibitors in the gathering and transportation pipelines, and reduce the labor intensity of on-site manual dosing. It is in line with the direction of the comprehensive development of oilfield additives.

Author-Wei Xin: cq17311.