Specification :

1. General Information
Oil layer protection is now a key technique in oil exploration and development, of which shielding transient blocking of drilling fluid is the first to be developed and applied. Application of this technique can turn the positive pressure difference of the oil layer, a harmful factor in oil layer protection, into a favorable factor, opening an important route in the protection of oil layer both effectively and economically. Whether there are highly dispersed micro particles that can be softened and transformed as filling particles to match QS-2 bridging filling particles in the mud is the key factor to apply the shielding force blocking technique.
Thanks to the breakthrough in manufacturing technology LFT-70 and LFT-110 with both advantages are developed. Test shows that the recovery rate of rock core permeability by adding 3% of LFT-70 ( or LFT-110) together with QS-2 is over 70% and the pollution depth is below 2cm. LFT-70 and LFT-110 have broad prospects in oil layer protection engineering.

2. Differences between LFT-70, LFT-110 and Ordinary Asphalt Powder
� The softening point is low. The value can be accurately found out by a measuring instrument.
� Oil soluble content is over 30% .
� Much higher oil soluble content over that of ordinary asphalt powder as it has, its dispersity is very good without floating conglomerations in the mud.
� For permeable and micro-crack leakage, its blocking capability is equal to special blocking agents.
� When added in, there is no foaming and no increasing of viscous shear in the mud.
� As the softening point is low, it appears in oily wet granules. No press, away from strong sun shine, and store in a cool and dry place.

3. Use
LFT-70 is fit for use in the oil and gas layer protection in wells 2000-3300m deep.LFT-110 is fit for use in the oil and gas layer protection in wells 3300-4000m deep. In addition, both aer fit for leakage blocking and collapse prevention in wells of every kind .It' s wise to use together with matching glue.
� Oil Layer Protection
( 1) At 100m before entering the pay bed adds in 1-2% of LFT-70 ( Or LFT-110) together with2-3% of QS-2 to pre-treat the mud for transformation which is to be used depends on the well temperature.
( 2) During drilling into the pay bed, add in the mud 5-10% concentration glue to maintain the required the concentration. At the same time add in polymers or sulfonated treating agent, water loss depressant.
� General Use
( 1) LFT-70 and LFT-110 are of strong capability in controlling filter loss. Mud cakes formed are thin and tenacious, of good greasy property and poor permeability, so that drill pipe sticking is effectively prevented. They are used to prevent sticking and control HTHP filter loss. Quantity to be added in is 1-1.5% together with proper quantity of depressing polymer treating agent and water loss depressant
( 2) LFT-70 and LFT-110 are capable of restraining the hydrolytic de-composition and dispersion of clay. They are used to prevent collapse of friable hard shale and stabilized well wall. Quantity to be added in is 1-1.5% together with proper quantity of high polymer.
( 3) For permeable and micro-crack formation the blocking result is remarkable. LFT-70 and LFT-110 are used to treat permeable and micro-crack leakage. Quantity to be added in is 1-1.5% together with proper quantity of QS-2 and FT-1.

4. Technical standard
Item Indexes
Appearance Black oily granule
PH e7
Water soluble % e20
Oil soluble % e30
Softening point ( LFT-70)  70-90
Softening point ( LFT-110)  100-120
HTHP FL, ml/ 30min d25

5. Storage and package
25Kg net sealed in 4-in-1 compound paper bag with plastic lining during storage and transport see that the bag is intact. But its property is not affected even if it becomes damp.