I. Brief Introduction of Product
Tight shale gas reservoir has the characteristics of low porosity and permeability, so it is difficult to conduct exploration and development. For most shale gas well, reservoir modification must be needed to acquire ideal production. At present, in foreign countries, the foremost stimulation method is friction-reducing fracturing, that is modifying the volume with fracturing fluid with friction-reducing water. The system of fracturing fluid with friction-reducing water is a brand new fracturing fluid system, which is aiming at modifying shale gas reservoir. In the United States and Canada, with the help of the above technology, obvious economic profit has been acquired and the traditional gel fracturing fluid has already been replaced.
Recent years, development of shale gas is becoming more and more important. As the technology to modify shale gas volume, fracturing fluid with friction-reducing water will enjoy broad prospects. The fracturing fluid with friction-reducing water actually is a kind of fracturing fluid with certain amount of proppant, and minute friction-reducer, surfactant, clay stabilizer and etc., also named slick water fracturing fluid.
During the recent one or two decades, due to fast development of the recovery of unconventional oil and gas reservoir home and abroad, and with the methods of volume modification, fracture and network modification and scale modification, so the consumption of slick water is usually large. For field space, high requirements are for fluid compound and storage. Therefore, on-line continuous fluid compound will be more and more urgent. Most of the original polymer friction-reducer is powder, in order to achieve instant dissolution and meet the requirements of fracturing, the dissolution must be needed to dissolve polymer friction-reducer or use reverse emulsion-polymerization to produce new kind of friction-reducer with emulsion character.
The product of our company is a high efficiency friction-reducer for shale gas slick water fracturing. It is a reverse emulsion-polymer with alkyl acrylamide, acrylic acid, and sulfonic acid and its derivate, uniform milky or light yellow liquid. Slick water system comprises high efficiency friction-reducer HDJZ-1, discharge aiding agent, clay stabilizer, and bactericide and antisludging agent.The product has the advantages of low friction resistance force, low swell, low damage, easy flowback, stable and fast swelling, good performance, easy preparation on line and excellentadaptability, and may meet the requirements of various shale gas or oil well for fracturing.

II. Performance Index
Overall Performance Index of Emulsion Slick Water:
●Friction-reducing Ratio, international advanced level;
●Low damage Ratio, viscosity: 2 ~ 30 mPa.s;
●Easy flowback, continuous and stable self-blowing flowback, saving large amount of expense;
●Easy preparation and operation;
●Low surface tension of flowback fluid, favorable for recovering and recirculating usage;
●High performance to price ratio.

III.Compatibility Test
Conduct compatibility test between HDJZ-1 emulsion friction-reducer andlong-lastinganti-swell agent, high efficiency discharge aiding agent, bactericideformaldehydeandinorganic clay stabilizer respectively. The results are in Table1and 2.
Table 1 Stability Test of HDJZ-1 Emulsion Friction-reducer

Table 2 Stability Test of HDJZ-1 Emulsion Friction-reducer with Other Addictives

IV. PerformanceEvaluation of Friction-reducing of Slick Water System
4.1 Lab Test Methods
Prepare 0.15% emulsion friction-reducer solution, test pressure drop inΦ15mm ascending pipe with different flow velocities under ambient temperature, and compare the results with clean water with the same velocity, so to determine the “relationship curve between shear rate and friction-reducing rate”.
4.2 Lab Test Result

 
Flow Rate Vs. Friction (Lab)

 
Collation Map of Friction Effect between Clean Water and Slick Water in 1000m, Φ50mm Continuous Oil Pipe 

Actual Friction Chart of Slick Water in 5 1/2″ Casing