1460739859-a0ddfe21-30ef-477d-a555-15c702cc3cb1

What is claimed is:

1. A catalyst for the polymerization of ethylene, comprising the following components and in combination:
a metallocene type transition metal compound represented by the following formula or wherein R1, R2, R3, R4, R5, and R6, which may be the same or different, each independently represent a hydrogen atom, a halogen atom, a hydrogen carbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a boron-containing hydrocarbon group, an alkoxy group, an aryl group, an aryloxy group, or an amino group; M represents a metal atom selected from group 4 to 6 elements of the periodic table; X and Y represent a hydrogen atom, a halogen atom, a hydroarbon group, an alkoxy group, an amino group, an amido group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group; A represents a ligand selected from a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a fluorenyl group, a substituted fluorenyl group, an azulenyl group, and a substituted azulenyl group; a and c are an integer of 2 to 10; and b and d are an integer of 0 to 10, provided that, if b or d is 0, carbon atoms represented by C* are each independently linked to a hydrogen atom, a halogen atom, or to a hydrocarbon group having 1 to 20 carbon atoms, a halogen-containing hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a boron-containing hydrocarbon group, an alkoxy group, an aryl group, or an aryloxy group, provided that atoms or groups linked to the respective carbon atoms may be the same or different; and
the following compound (a), (b), (c), or (d)
(a) an aluminumoxy compound,
(b) a Lewis acid,
(c) an ionic compound which can be reacted with the component to convert the component to a cation, or
(d) an ion-exchangeable layered inorganic compound.
2. The catalyst for the polymerization of ethylene according to claim 1, wherein the component is a metallocene type metal compound containing at least a tetrahydroindenyl derivative having a substituent at the 2-positon, a hexahydroazulenyl derivative having a substituent at the 2-position, or an octahydrofluorenyl derivative.
3. The catalyst for the polymerization of ethylene according to claim 1, wherein the component is an ionic-exchangeable layered inorganic compound (d).
4. The catalyst for the polymerization of ethylene according to claim 1, wherein the aluminumoxy compound (a) is a compound represented by the formula or:
wherein p is a number of 0 to 40 and R10 represents a hydrogen atom or a hydrocarbon residue.
5. The catalyst for the polymerization of ethylene according to claim 1, wherein the ionic compound (c), which can be reacted with the component convert the component to a cation, is a compound represented by the formula
KeZe(6)
wherein K represents an ionic cation omponent selected from carbonium, tropylium, ammonium, oxonium, sulfonium, and phosphonium cations, cations of metals which as such are likely to be reduced, and cations of organometals; Z represents an anionic component which is a counter anion against a cation species converted from the component and is selected from organoboron compound, organoaluminum compound, organogallium compound, organophosphorus compound, organoarsenic compound, and organoantimony compound anions.
6. The catalyst for the polymerization of ethylene according to claim 15, which further comprises an organoalumininum compound as component.
7. The catalyst for the polymerization of ethylene according to claim 6, wherein the component is a compound represented by the formula
A1R11mX3m
wherein R11 represents a hydrocarbon radical having 1 to 20 carbon atoms; X represents a hydrogen atom, a halogen atom, an alkoxy group, a siloxy group, or an amido group; and m is an integer of 0<m<3.
8. A catalyst for the polymerization of ethylene, comprising the catalyst for the polymerization of ethylene according to claim 15, wherein the component is any one of the compounds (a) to (c), in combination with the following component:
an organic or inorganic particulate porous carrier.
9. A process for producing an ethylene polymer, comprising the step of polymerizing ethylene or ethylene and an -olefin having 4 to 20 carbon atoms in the presence of the catalyst for the polymerization of ethylene according to claim 1 or 8.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1) A method for constructing a kinetic model allowing to estimate the mass of hydrogen sulfide produced by a rock containing crude oil and subjected to contact with steam at a temperature T for a contact time t, generating an aquathermolysis reaction, characterized in that the method comprises the following stages:
a) describing the rock, the crude oil and the hydrogen sulfide produced according to a characterization by chemical compound fractions comprising at least the following fractions:
the NSO, aromatics and resin fractions to describe the oil,
the insolubles fraction containing compounds that are insoluble in dichloromethane and n-pentane, to describe the rock,
the hydrogen sulfide fraction to describe the hydrogen sulfide,

b) defining a kinetic model describing, from kinetic parameters, the mass of hydrogen sulfide produced as a function of said contact time t, as a function of said temperature T and as a function of the evolution of the sulfur distribution in said chemical compound fractions, wherein:
at least part of the sulfur contained in said NSO fraction produces hydrogen sulfide and at least another part is incorporated in said insolubles and aromatics fractions,
at least part of the sulfur contained in said resin fraction produces hydrogen sulfide and at least another part is incorporated in said insolubles and aromatics fractions,
all of the sulfur initially contained in the oil and the rock is entirely dispersed in at least one of said chemical compound fractions during aquathermolysis,

c) calibrating said kinetic parameters from aqueous pyrolysis experiments carried out on at least one sample of said rock.
2) A method as claimed in claim 1, wherein at least as many pyrolysis experiments as there are kinetic parameters to be calibrated are carried out.
3) A method as claimed in claim 1, wherein said aqueous pyrolysis experiments are carried out for various temperatures and various contact times.
4) A method as claimed in claim 3, wherein the various temperatures are selected within a range wherein aquathermolysis has notable effects.
5) A method as claimed in claim 3, wherein the various temperatures are above 200\xb0 C.
6) A method as claimed in claim 3, wherein the various temperatures are below 300\xb0 C.
7) A method as claimed in claim 3, wherein the following values are measured after said pyrolysis experiments:
the mass of hydrogen sulfide produced for each temperature and each contact time between the steam and the oil,
the sulfur mass distribution in each one of said fractions.
8) A method as claimed in claim 7, wherein the sulfur mass distribution in each fraction is measured by extraction and separation of the fractions by means of solvents, then by weighing and elementary analysis of the fractions.
9) A method as claimed in claim 7, wherein the mass of hydrogen sulfide produced after said pyrolysis experiments is measured by gas chromatography.
10) A method as claimed in claim 1, wherein initial conditions of said kinetic model are determined from rock samples by separating, prior to pyrolysis, said fractions by means of solvents and by performing elementary analyses of said fractions thus separated.
11) A method as claimed in claim 1, wherein said kinetic parameters are calibrated by means of an inversion technique.
12) A method as claimed in claim 1, wherein the mass of hydrogen sulfide produced by a petroleum reservoir during crude oil recovery by steam injection in said reservoir is estimated by carrying out the following stages:
calibrating said parameters from rock samples from said reservoir,
estimating said mass of hydrogen sulfide produced by said reservoir at any time, by means of a reservoir model and from said kinetic model.
13) A method as claimed in claim 12, wherein it is checked that the mass of hydrogen sulfide produced by said petroleum reservoir remains below the legal maximum level.
14) A method as claimed in claim 12, wherein steam injection conditions necessary to reduce H2S emissions are determined.
15) A method as claimed in claim 12, wherein processes for re-injecting H2S into the reservoir are dimensioned.
16) A method as claimed in claim 12, wherein wellhead acid gas processing plants are dimensioned.