Advantages of ceramic proppant

Because of quartz sand and sand-based proppants with practicality and low cost, they become the most popular maide natural gas fracturing proppant. However, studies on the recovery of the Society of Petroleum Engineers released in a show that has a higher strength and uniform size and shape than other types of ceramic proppant proppant can offer higher yields (SPE 77675). For different types of oil and gas reservoir conditions, the use of CARBO's ceramic proppant for fracturing oil and gas wells have maide natural gas fracking been able to maintain a good yield.

Resin-coated sand used in the Proppant

Resin coated sand as the proppant stimulation mechanism for hydraulic fracturing , the coated particles of the resin is filled in by generated hydraulic fractures in the reservoir condition , the coating softens and adjacent coated particles adhesive layer , and finally cured resin hardens into non- plastic state , particle maide fracturing proppants adhesion in the contact point region , a fairly stable and has a certain mechanical strength and permeability of the structure in the fracture . Electron microscopy samples found completely coat the surface of the particles of the resin after curing , the adhesive strength and in the section between the larger particles , which not only eliminates the high stress concentrations , but also to prevent the resin -coated high stress Ying produce fine grain under free . In short , the main reason for the resin coating as maide ceramic proppant sand proppant are the following : a resin-coated sand proppant can be prevented and the discharge tube or cracks around the proppant emptying . Deformable resin coating to avoid and prevent proppant crushing softer formations embedded . Tough coating having chemical stability oil , saline, and most of the acid. Resin-coated sand in the closure stress and temperature effects , fixed cracks in favor of oil production . Laboratory experiments on the physical characteristics of the resin coated sand were evaluated.

Ceramic proppant

The main raw materials are bauxite, while China is a country rich bauxite , bauxite distribution is highly concentrated, Shanxi, Guizhou, Henan and Guangxi in four provinces (regions ) ceramic proppant suppliers accounted for 90.9% of the total reserves of the country's total reserves ( Shanxi 41.6% , 17.1%, Guizhou , Henan, 16.7% , 15.5%, Guangxi ) , and the rest owned bauxite 15 provinces, autonomous regions and municipalities accounted for only 9.1% of the total reserves of the country's total reserves. Chinese ceramic proppant manufactured good support for its ability to gradually replace conventional proppant sand, into the U.S. market . So far, the bauxite proppant Chinese -made ceramic proppant ceramic proppant has occupied the entire North American market share of 13% , the average annual business volume of $ 3 billion .

Fracturing sand geological factors

Geological factors refers to unconsolidated sandstone formations geological conditions , such as the content and distribution of cement , cement type , Diagenesis and geological proppants for hydraulic fracturing age and so on. Generally speaking , the later geological age , the less cemented mineral formations , sand cementation worse , the more uneven distribution of sand strata in the more serious exploitation ; different types of formations , formations cement cementing force of the fluid within the trap adhesion , friction and gravity stratigraphic formations bond strength of particulate matter formation between particles of the decision itself is different , smaller formations bond strength , sanding more serious. Depending on the size of the bond strength stratigraphic formations of sand divided into three types :
( 1 ) flow sand formations : the unconsolidated formations . No cement between the particles , the bond strength depends on only a small stratum of sand and ambient fluid adhesion strength trapping pressure , formation sand under certain conditions can flow.
When the event of such formations prone borehole collapse , causing sticking , buried underground drilling accident , proppant manufacturers openhole completions with conventional gravel pack method, prone to the phenomenon of formation sand spit , resulting in lower reservoir sand buried screens less than borehole bottom sand plug , gravel and sand strata intermixing , and even the formation sand into the cavity through a sieve slit screens , stuck pipe caused the accident . Therefore , the packer must grit , high density and thickening special technical measures completion completion fluid.
Immediately after the operation and continuous sand , sand wellhead relatively stable.
( 2 ) partially cemented strata : less cement content of such formations , formation sand partially cementation poor, low intensity . Such formations encountered while drilling , drilling fluids can be added in a suitable temporary blocking agent to stabilize the wall , to prevent formation collapse , avoiding the sharp drop in speed and downhole drilling accident, under certain conditions , you can use an openhole gravel pack completion method wells.
This formation wells through formations in the vicinity of borehole spalling in the mining process , the gradual development of the formation of caves. Flaking pieces easily fill the wellbore formation sand into the bottom pocket , plug tubing, buried reservoirs . After the oil sand production rule as shown in Figure 6-2 , the performance of the large amount of sand volatility changes . If we do not control them , then producing layer near mudstone, shale sandwich out of the hole increases due to peeling , causing the near-wellbore region of mudstone , shale and sandstone three kinds flaking material intermixing , permeability decreased production decline . If left unchecked, may cause formation collapse , drop cap , casing damage , serious consequences wells scrapped .

Volume fracturing mechanism

The reservoir through hydraulic fracturing implementation of the transformation , while the formation of one or multiple main crack , so expanding natural fractures and brittle rock shear slip , to achieve communication of natural fractures , rock bedding , as well as cracks in the main lateral force the formation of secondary high density ceramic cracks and secondary cracks in the secondary cracks continue to form secondary branches , and so on , forming a network of natural fractures and artificial crack crack intertwined . Thus the effective reservoir seepage can be broken to achieve a comprehensive transformation of length, width and height of the three-dimensional direction , increasing the flow area and diversion can increase initial production and ultimate recovery . Volume fracturing proposed reform is based on the volume of this new modern theories put forward . Transformation of the concept of volume appears to subvert the classical fracture theory is the basis for the development of the modern theory of fracturing . Conventional fracturing technology is built in to the linear elastic fracture petroleum proppant mechanics based on classical theory of technology. The most important feature of this technology is the assumption that the artificial fracturing of open -type fracture initiation and formation of cracks in the wings symmetrical perforation intervals along the wellbore . In order to achieve an improvement in the main reservoir seepage cracks capacity , the main vertical cracks in the matrix to the fracture is still " a long distance " seepage , the biggest drawback is the main vertical cracks seepage ability did not improve , the mainstream channels can not be improved the overall flow capacity of the reservoir . Although research studies in the latter part of the non-planar crack extension , but it is limited in many cracks , analysis and characterization of cracks , joints and other types of complex fractures of bending , but theoretically no breakthrough . The " volume reform" according to its definition, the formation of cracks in the system is a complex network , crack initiation and propagation of cracks are tensile cracks of simple , but there are still cut, slip faulting and other complex mechanical behavior .

With the minimum flow shale gas

Horizontal well completions experienced proppant production completions to shift from the casing completions , shown in Figure 1. Early horizontal wells usually 114.3 00 ( Bucket 1 / / > or 139.7 00 "1 / / > casing completions , fracturing drillable bridge plug using multi -stage fracturing . 2012 abroad tend to use openhole horizontal wells multistage fracturing operation mode completions , fracturing stages gradually from 5 to 7 , up to 20 or more. Barnett shale gas reservoirs in horizontal well development had tried resin coated sand proppant completions

Strategic frac proppant of shale gas revolution "in the United States

Close to a period, "the shale gas revolution" will trigger a American energy independence become a hot topic. "Shale gas revolution" can touch the excitement in the United States, because the energy in the weight has always been very high in the American foreign strategy. The fourth Middle East war in 1973 the Arab oil producers to western oil oil fracturing proppant result in America after the economic crisis, the U.S. government's emphasis on energy independence is greatly increased. Under George w. bush even formed by the spearhead of vice President cheney energy task force, dedicated energy independence. In recent years, because of the technological petroleum proppant, the considerable reserves of unconventional oil and gas resources, all of a sudden release huge value. In 2011, the United States for the first time a net exporter of oil products. In 2012, the shale oil production to 1 million barrels a day. In 2035, the U.S. shale gas production is expected to reach 49% of its gas production. The United States, according to the international energy agency published a report that will be around 2020 to become the world's largest oil producer, to around 2030, the United States will make North America area net oil exports. Analysts, in turn, points out, "the shale gas revolution" if true, would lead a new round of unconventional oil and gas resources development tide, in the americas formed in "Canada's oil sands, heavy oil shale gas in the United States - venezuela, Brazil's pre-salt oil" for the axis, the north-south emerging energy belt.

Ceramic proppant

Is a ceramic particle products, mainly to increase support for Maide Ceramics oil and gas production , environmental products, its mineral composition is alumina , silicate and iron - titanium oxides , mostly cylindrical spherical , high strength, Deep reservoir fracturing high closing pressure applied , for the deep well , to improve the flow ultralight weight is also used to make trailing proppant , is a natural quartz sand, glass beads alternative products , metal balls and other low- strength proppant oil and gas production has a positive effect . Ceramic proppant is a high- strength ceramic particulate products. Mainly used in oilfield fracturing to increase oil and gas production. And other materials proppant compared to ceramic proppant has what advantages: smooth surface, high fracture strength , acid and alkali , high conductivity and durability and other characteristics.

Classification of coatings

A wide variety of synthetic resin paint, there are ultra lightweight proppant two kinds of classification methods:
(1) according to the main film forming material classification
Due to the resin is different and each has its characteristics (table 1). Alkyd resin coating production of the largest, fastest growing acrylic resin coatings, amino resin coating, epoxy resin coating, polyurethane coating production is bigger also, this is constitute the five varieties of synthetic resin coating.
(2) the classification according to the oil well fracking with the dispersion medium
Can be divided into three categories of solvent, water type, no solvent (table 2). Solvent-based coating production of the largest, widely used, but because of the need to use a large number of organic solvents, environmental pollution, are being high solid coatings, water type coatings, powder coatings and radiation curing coating gradually replaced. Sometimes call this a few kinds paint coating of saving energy and low pollution, save resources, is the coating product of new variety.

Ceramsite performance characteristics

Ceramsite performance characteristics
Oil and gas well sand production is one of the important problems facing the loose sandstone reservoir. The petroleum proppant of sand production is mainly manifested in the following four aspects:Oil and gas well production or shut down
Oil and gas well sand production, easy to cause sand buried reservoir, sand plug tubing and manifold and storage tanks in the sand, which was forced to shut down operations. Rinse the sand buried reservoir, sand plug removal of tubing, both time-consuming and expensive, also can't completely solve problem. To resume production soon and need to work, live, shorter production cycle and make the oil and gas production, homework cost huge increase, serious economic loss.
The ground and underground equipment and pipeline abrasion
Hydrocarbon flow carried in the formation of sand main high density ceramic is sio2, the hardness is very high, is a destructive strong abrasive, can make the pump seat wear and no seal, valve ball pitting, rod and pump cylinder strain, ground valve failure, serious erosion, oil transfer pump impeller thus forced to shut-in homework, replace or repair the equipment, cause the loss of production, the cost is rising.
Casing damage to oil and gas Wells scrap
Serious sand production for a long time in outside casing a huge hole, inner and outer force imbalance lead to sudden formation collapse, cause casing deformation, light weight, casing was wrong fault collapsing, lead to oil and gas Wells of scrapped.
Destroy the formation of the original structure or cause the formation permeability near wellbore area of serious decline
Oil and gas well after the sand, sand migration, formation sand near wellbore area of sedimentation is more, far wellbore area becomes loose structure. Caused a significant reduction in the formation permeability near wellbore area, oil and gas well production decline.
Solve the problem of oil and gas Wells sand production, must be based on the early prevention and control, to reduce the damage to the reservoir cementing