Top Select > Services & Products > Production Enhancement

Hydraulic Proppant Fracturing

In hydraulic proppant fracturing of formation, in contrast of acid fracturing, uses a proppant to hold the fracture open and create a high permeability low path along which fluids flow into the well. In a hydraulic fracturing treatment, a high-viscosity fluid is injected into the well at treating pressures that are higher than the so-called formation breakdown pressure (practically speaking, the minimum horizontal stress.) Fluid injection continues for some time beyond this initial propagation, and when the created fracture is wide enough to accept them, solid particles (sand or some other type of proppant material) are injected simultaneously with the carrying fluid. The proppant material gradually fills up the fracture so that when the pumps are stopped, the fracture faces gradually close on the proppant.

Top Select stimulation team has successfully fractured above 450 wells of different type of reservoirs around the world. We appreciate the opportunity to provide you with technical proposal and looks forward to being of service to you.

Chemicals & Additives
Service Equipment

Hydraulic Fracture-Water Based Frac Fluid System-TPWBF®

TPWBF® fracture fluids are the most commonly used for hydraulic fracture in sandstone formation; which is developed by using guar gum powder as a thickening additive having high viscosity and water solubility. Moreover crosslinking agents are used to significantly increase the effective molecular weight of the polymer. TPWBF® has high stabilities in a broad-range temperature environment, cost effective and easy for field preparations. Controllable delayed-time for crosslinking and gel-break time. TPWBF® provides high level of gel-break with low residuals in the pore and fracture, which minimizes the formation damage caused by fracture fluids. Its performance for carrying proppant promotes TPWBF® to be used as an appropriate fracture fluid.

BENEFITS

Controllable delayed-time which minimizes the frictions of TPWBF® used for deep-well fracture
High stability in shear resistance and high temperature applications to meet challenges from large-scaled operations
Low residual content, low formation damage, and high volumes of fracture fluid flow-back after fracture
Low water-locking rate
Low core damage after fracture

Items		Specifications
Items		Low-temperature 30˚ C～60˚ C	Mid-temperature 60˚ C～120˚ C	High-temperature 120˚ C～180˚ C	items	Low-temperature 30˚ C～60˚ C	Mid-temperature 60˚ C～120˚ C	High-temperature 120˚ C～180˚ C
Density, g/cm³		0.97～1.03			Demulsification Ratio, %	≥ 98
Cross-linking time, s		30～240	40～360	120～600	Surface Tension of Gelout Fluid, mN/m	≤ 25.0
Shear stability	Shear time, min	60	60	80	Interfacial Tension, mN/m	≤ 1.0
Shear stability	Apparent viscosity, mPa.s	100	100	50	Residue Content, mg/L	≤ 98	≤ 135	≤ 220
Core Damage Ratio, %		≤ 21			-	-

Hydraulic Fracture-VES Fracture Fluid System-TPVES®

Viscoelastic surfactant (VES) fluids have been widely used as fracturing fluids for more than a decade because the fluids exhibit excellent rheological properties and maintain low formation-damage characteristics compared with crosslinked-polymer fluids. Because of its non-wall-building property, TPVES® fluid has much higher fluid leak-off into the reservoir matrix than wall-building polymer fluid. The fundamental characteristic of all surfactant is that within a single molecule, there is typically an oil-soluble hydrocarbon chain and a water-soluble group. When surfactant concentration significantly exceeds a critical level and an electrolyte is presented, VES-type molecules will aggregate and form elongated chains or micelles. The surfactant molecules in the chain or micelle are continuously exchanged with free molecules in the solution or those from other chains or micelles. The surfactant exchange results in dynamic rod-like chains with constant breakage and recombination like ‘living polymer’. The rod-like micelles can interact to form a network exhibiting viscoelastic behavior. TPVES® was developed by Top Select R&D group and successfully applicated in South America and Asia oil and gas field.

BENEFITS

Polymer-free characteristic lead to no residues, low level of formation damage and low frictions to reduce the pumping pressure.
Gel-break completely and automatically when encountered with oil or water in formation.
High ratio of flow-back.
Clay stability and compatibility friendly.

Items		Specifications	Items	Specifications
Application Temperature (℃)		30˚ C -120˚ C	Viscosity of Gel-Break Fluid, mPa.s	≤ 5.0
Cross-linking Time, s		30-60	Surface Tension of Flow-Back Fluid , mN/m	≤ 27.0
Shear stability	Shear time, min	60	Interfacial Tension, mN/m	≤ 1.0
Shear stability	Apparent viscosity, mPa.s	≥ 30	Residue Concentration, mg/L	None
Damage Ratio on Cores, %		≤ 11.5	-	-

Hydraulic Fracture-Slick Water-TPSLW®

Hydraulic fracturing is essential for economic production in tight gas and shale gas reservoirs due to their low permeability nature, also could be used for Pad fluid and over-flushing fluid to reduce the friction. Friction reducers are commonly used in slick water fracturing operations to minimize energy loss due to tremendous amount of friction between tubular goods and water or brine solutions during the pumping of very high rate of fluids. TPSLW® Slick water fracturing has been successfully performed in shale and tight gas reservoirs using low viscosity fluid, usually water with friction reducers. TPSLW® Slick water fracturing has the advantage of reducing formation damage and generally being less expensive than conventional gel.

BENEFITS

No residues, low level of formation damage and low frictions to reduce the pumping pressure.
Low viscosity and low surface tension, extremely easily flow back.
Extremely simple recipe and easily-operated mixing on the fly.
Low costs and economical benefits.

Item	Specifications	Item	Specifications
Application Temperature (℃)	30˚ C -120˚ C	Interfacial Tension, mN/m	≤ 1.0
Viscosity, mPa.s	5-9	Residue Concentration, mg/L	None
Core Filtration Coefficient, m/min (Core 0.2mD)	2.132×10-4	Damage Ratio on Cores, %	≤ 10.2
Surface Tension of Flow-Back Fluid , mN/m	≤ 21.0	-	-

Equipment Layout for Fracturing Treatment

In hydraulic proppant fracturing of formation, in contrast of acid fracturing, uses a proppant to hold the fracture open and create a high permeability low path along which fluids flow into the well.