2727 FM 521, FRESNO, TX 77545 281- 431- 0670 OFFICE

281- 710- 7934 FAX

PolarProp Application Histories

PolarProp is Santrol’s curable resin coated sand, designed for low temperature/low stress

wells for flow-back control, sand control and conductivity improvement. PolarProp can

be used in wells 16-80 oC, but if the bottom hole temperature is less than 36

oC, activators

is required for best performance. Due to its excellent multi-layer coating technology, it is

compatible with most of the fracturing liquids. PolarProp was widely used worldwide

since it was released in 2000, several case histories is following.

Flow-back Control in Canada

This application was part of a shallow gas development project near Brooks, Alberta,

Canada. The problem with their wells is that in these shallow wells (400-800m), the

closure stress is very low, so after the job there was up to 20% of proppant flowed back

to the wellbore, this dramatically reduce the production rate, wells have to be cleaned out

before put back to production, money has to be spent on the disposal of the flowbacked

proppant. Then the service company Trican Well Service Ltd and the operator Startech

Energy Incorporated were working together on the project to solve the flow back issues.

Eventually, about 130 wells were stimulated in Medicine Hat (MH) and Milk River (MR)

formation by using Resin Coated Proppant, Fiber Element and Surface-Modification

Agent for comparison.

Results showed that PolarProp is the most efficient flow back control technique. It

provide the best average productivity index associate with no wellbore cleaning and

proppant disposal cost. 2. Also, he use of proppant flowback control has the added

benefit of lessening the environmental impact of the project.

Flow-back and Sand Control in Western China

This project started in 2007, which is even before Santrol Yixing’s start-up. So we

shipped PolarProp from Santrol’s Mexico Plant to China. In 2008, Santrol Yixing started

to supply western oilfield, included Tuha, Keramay, Qinghai from PetroChina with both

PolarProp on sand and intermediate strength ceramic until today.

The problems with Western Oilfield in China are

2727 FM 521, FRESNO, TX 77545 281- 431- 0670 OFFICE

281- 710- 7934 FAX

1) Oil production decline due to formation sand producing back and plugging

wellbore.

2) Attempts to remove produced sand and control sand production from wellbore

failed to be effective.

3) Utilized fibers in gravel pack treatment with no positive results.

4) Many pay zones were abandoned. Upper zones were opened and experienced the

same problems..

After communicating with Santrol in 2006, PetroChina Western Oilfield start their first

trial in 2007 by using 30-50% PolarProp to tail-in and it was succeeded to control the

formation sand and proppant flowback, so far the efficiency by using PolarProp is 90%

for the approximately 40 wells that they fractured. However, this is because they only use

30-50% RCP to tail-in, which sometimes is not sufficient for sand control, especially

when you have multi-fractures. We believe if they can 100% use PolarProp, the

efficiency will be better than 90%. The well conditions and performance is below,

Typical Well Data: Depth 1500 to 1600 m

Permeability 75 to 110 md

Porosity % 25%

Formation Type Unconsolidated Sandstone

Production Type Oil

Oil Saturation 60%

BHT 45 – 50 oC

Closure Pressure 25 - 40 Mpa

Treatment Design 60% Uncoated ZG, tail-in with 40% ZG PolarProp

Well # Production Before,

t

Production After,

t

Fracturing Effective Time,

day

Yudong2-53 0.60 4.98 356

Yance6-4 2.66 23.31 640

Yan6-7 6.12 19.77 287

Yan603 3.62 12.32 354

Wen5-504 0.00 19.37 270

Wen5-512 0.14 5.28 270

Wen2-8c 3.53 8.04 285

To summarize, PolarProp can effectively help to control proppant flowback and

formation sand. And most important is that it extends the well life by maintaining good

conductivity which is best character of using Resin Coated Proppant. Because the

2727 FM 521, FRESNO, TX 77545 281- 431- 0670 OFFICE

281- 710- 7934 FAX

fracturing effective time in western China used to be 5-7 months, from the number above

it is found 9-12 months production is normal by using PolarProp.

Flow-back and Sand/Coal Powder Control in CBM, Shanxi, China

20/40 Polarprop has been successfully used by Far East Energy China for its Coal Bed

Methane (CBM) application since 2008. The well condition in the field is as following:

Well Vertical Depth: 500 – 800m (Declined well)

Bottom Hole Temperature: 30oC

Closure Stress: 2-4 MPa

Fracturing Fluid: Slick Water

Issues: Proppant Flowback and Coal Powder Sandout.

In early 2008, after reviewing the well conditions, Santrol suggested Far East Energy to

apply 20/40 Polarprop with Superset Activators all the way for the fracturing process to

stop proppant flowback and coal powder sandout problem for the first 3 wells’ trial. But

after considering the cost of the fracturing job, eventually Far East Energy chose to tail-in

20% of 20/40 Polarprop after pumping 80% of 40/70 Sand in the front for the total

proppant volume of 66,000lb. The shut-in time is 24hrs and the job was done in May,

2008. Then it showed big increase on the water production for 2 of the three wells, but

the third one didn’t have big increase, inversely, some of the proppant flowed back and

the coal powder keep producing.

In April 2009, we met with the engineers from Far East Energy. We reviewed the past

jobs and focused on the future jobs this year. The resonation was achieved after analyzing

the geometry complexity of the CBM formation. Since the coal seam is full of micro

channels and cleats, the tail-in process can not make sure the raw frac sand stay in the end

of the fracture and the coated stay behind to stop it from flowing back. There is a huge

chance that the raw frac sand and the coated mixed together, or the raw stayed in one

small fracture and the coated stayed in another branch fracture. This is why there was still

flow back problem with the wells being fractured.

Then Santrol strongly recommended them to apply 100% 20/40 Polarprop for their new

jobs in late May. Also, the concentration of the Superset Activator was recommended to

reduce to 0.8% from 1%.

In May 2009, the three wells were fractured with 100% 20/40 Polarprop (858000lb per

well) plus 8% Superset C by the fluid volume. All these three wells were shut in for 24hrs

and huge water production increase was observed after opening the well. The wells are

2727 FM 521, FRESNO, TX 77545 281- 431- 0670 OFFICE

281- 710- 7934 FAX

producing 1000-2000 m3/day gas now while wells operated by others in this area have

average production rate of 500-700 m3/day.

Overall, Santrol’s Polarprop is succeeded to be applied in different formations worldwide

for

1. Stopping proppant flowback

2. Stopping coal powder sandout

3. Reducing water production time

4. Improve proppant strength

5. Sustaining well life

And Santrol’s best quality product and insistent technical service are the assurance of

different projects success.

Xintang Wang

Technical Support Manager, Asia

Byron Smith

V.P. of International Operation