A kind of method of Environment-protecting Drilling Fluids granularity optimizationTechnical field
The present invention relates to oil drilling auxiliary chemicals field, in particular to a kind of side of Environment-protecting Drilling Fluids granularity optimizationMethod.
Background technique
It is analyzed according to statistics, brill Well Completion Engineering of Oil Reservoirs occupies 40 ~ 60% with modern oilfield prospecting developing totle drilling cost, boresThe quality of well construction quality directly influences obtainable economic benefit.Wellbore stability, mud cake quality, drilling speed in drilling processSpeed, down hole problem prevention and processing all be unable to do without property of drilling fluid control.In drilling process, need at any timeRegulate and control the performances such as density, the viscosity of drilling fluid, keeps the stability and greasy property of drilling fluid system, enhance the leak-off of drilling fluidWave making machine adjusts the performance of drilling fluid when complex situations occurs in underground in time.The properties of drilling fluid are all solid with drilling fluidThe distribution situation of phase granularity has direct or indirect relationship, by adjusting mud solid phase granule content, size, distributionSituation and gradation relationship can largely influence the properties of drilling fluid.
The solid particle in drilling fluid is scattered in as the solid phase in drilling fluid, and there are mainly two types of its sources, first is that comingDerived from the landwaste for the rock generation that is broken, second is that be artificially added for drilling technology requirement.In drilling process, in drilling fluidThe size distribution of solid phase particles has a very big impact the traditional performance parameter and oil layer protection performance of drilling fluid.It can be with shadowRheological characteristic, the size of the quality of mud cake quality and filter loss for ringing drilling fluid, to drilling technology challenge (such as mud shale and coalThe collapsing of layer, undergauge, bit freezing, pressure excitement etc.) have a significant impact, especially deep-well, as drilling cuttings etc. is ground for a long time,Solid concentration increase inferior, solid phase particles size distribution are unreasonable in drilling fluid, it is easy to the performances such as rheological characteristic and dehydration occurSituation out of hand influences the safety of underground.Solid phase particles size distribution is unreasonable in drilling fluid also very formation damageIt is big to influence.Drilling fluid particle size distribution first has a major impact mud cake quality, and adjustment drilling fluid particle size distribution can shapeAt thin and compact high-quality mud cake.Temporarily stifled being mainly characterized by utilizing in drilling fluid of conventional shielding has solid phase particles and stores up to oil gasSome bridge formation grains to match with pore throat blocking mechanism are artificially added in the laws for plugging of layer into drilling fluid as neededSon, particle filled composite and deformation particle, so that these particles is rapidly formed around the borehole wall, effective, permeability is almost nilShading ring, prevent subsequent job entry well fluid in solid, liquid phase invaded formation.But currently used technology only only accounts forThe relationship between material and formation pore throat is temporarily blocked up in shielding, and there is no consider that already existing solid phase particles are to temporary in drilling fluidThe matched influence of blocking agent.By using level Four solid control equipment in drilling process, certain effect, but being directed in measure are achievedProperty it is insufficient.
Existing researcher proposes the method for carrying out size distribution adjustment for reservoir.Application No. is201310453524.1 patent proposes the maximum pore throat diameter D90 according to target reservoir, to drilling fluid and blocks screenerThe analysis of size distribution curve filters out drilling fluid and blocks the grain diameter proportion of screener.Application No. isThe Low Damage grain size distribution that the patent of 201610881250.X proposes high temperature ultradeep well reservoir aggravates water-base drilling fluid, is applicable inIn the drilling of the long net horizontal section of shale of microcrack development.Its technical solution is to prepare the raw materials used component of the drilling fluid and containAmount: bentonite 13.5-15；Sodium carbonate 0.675-0.75；Calcium oxide 4.5-5；Transporting agent 2.7-3；Sulfonated phenol formaldehyde resin 45-50；Sulfonated lignite resin 45-50；Sulfonated lignite 45-50；Sefstromite powder and millimicro barite adjust density to 2.50g/cm3；ProfitLubrication prescription 27-30；Without infiltration borehole wall stabilizer 27-30；Nanometer calcium carbonate 27-30；Anti-sloughing agent 18-20；Tap water 900-1000.FirstAfter having configured clay-based slurry, then in 500r/min it is added with stirring calcium oxide, sequentially adds above-mentioned inorganic agent after continuing stirring, thenRegulation system density is 2.5g/cm3It finally prepares to form Low Damage grain size distribution exacerbation water-base drilling fluid.These researchs are to brillThe adjustment of well liquid size distribution plays important impetus, but fails the optimization that size distribution is carried out for environment-friendly type inorganic agent,Or it need to be further clarified in terms of size distribution form, size, content.
Summary of the invention
In response to the problems existing in the prior art, the purpose of the present invention is to provide a kind of sides of Environment-protecting Drilling Fluids granularity optimizationMethod, this method optimize drilling fluid size distribution using varigrained nontoxic particle, form high-quality mud cake in the borehole wall, haveConducive to safely and fast drilling well, it is suitable for the fields such as the leak stopping of oil drilling leakage type, borehole wall reinforcing.
In order to reach the purpose of the present invention, the technical scheme is that be achieved:
At room temperature, drilling fluid is added in nano-particle and subparticle, then high-speed stirred 30min ~ 60min, makes to be added above-mentionedDrilling fluid size distribution is in normal distribution within 20 μm after particle, and whole is in bimodal distribution, and it is excellent that drilling fluid granularity can be realizedChange.
The drilling fluid includes 3 ~ 5%wt sodium bentonite, 1 ~ 3%wt sulfonated phenol formaldehyde resin (SMP), pH=7 ~ 10.
The nano-particle is the combination of one or more of bentonite, nanometer calcium, nano-silicon, and particle size range is 2~5μm, 0.1 ~ 5%wt of content in drilling fluid；The subparticle is the combination of one or both of calcium carbonate, bluestone powder, grainDiameter range is 5~20 μm, 0.1 ~ 8%wt of content in drilling fluid.
Bentonite of the bentonite after hydration process in the nano-particle.
The bentonitic hydration process is at room temperature, bentonite to be configured to the bentonite slurry of 8-12%wt, then waterChange 20-30h.
The present invention has the advantage that compared with prior art
(1) nano-particle and subparticle that the present invention uses, the materials such as opposite pitch, nanoemulsions, environment friendly is stronger,Asepsis environment-protecting, cost is relatively low, and granularity optimization is easy to execute-in-place；
(2) present invention can be used in the solidification of the oil drilling borehole wall and microcrack leakage stopping technology, improve filter cake intensity.
Detailed description of the invention
Attached drawing 1 is the granularity optimum results figure of an embodiment of the present invention.
Specific embodiment
The present invention is further explained in the light of specific embodiments.
Embodiment 1:
At room temperature, bentonite is configured to the bentonite slurry of 10%wt, aquation takes 100ml and 1000 mesh calcium carbonate 50g mono- afterwards for 24 hoursIt rises and is added in 1000ml drilling fluid, carry out high-speed stirred 30min, the optimization of drilling fluid granularity can be realized.Wherein drilling fluid includes4%wt sodium bentonite (hereinafter referred to as sodium soil), 2%wt sulfonated phenol formaldehyde resin (hereinafter referred to as SMP), pH=8.
Embodiment 2:
At room temperature, the bentonite slurry 80ml, nano-silicon 10g that same procedure is prepared in above-described embodiment 1 are taken；800 mesh of subparticle1000ml drilling fluid (comprising 4.5%wt sodium soil, 2.7%wt SMP, pH=9) is added in calcium carbonate 50g, 1200 mesh calcium carbonate 50g, intoThe optimization of drilling fluid granularity can be realized in row high-speed stirred 50min.
Embodiment 3:
At room temperature, the bentonite slurry 80ml, nanometer calcium 10g that same procedure is prepared in above-described embodiment are taken；500 mesh of subparticle is green1000ml drilling fluid (comprising 4.5%wt sodium soil, 1.5%wt SMP, pH=7.8) is added in mountain flour 50g, 1200 mesh calcium carbonate 50g, intoThe optimization of drilling fluid granularity can be realized in row high-speed stirred 40min.
Embodiment 4:
At room temperature, nano-silicon l0g, nanometer calcium 10g are taken；1000ml drilling well is added in 500 mesh bluestone powder 50g, 800 mesh calcium carbonate 50gIn liquid (including 3.5%wt sodium soil, 2%wt SMP, pH=8.8), high-speed stirred 55min is carried out, it is excellent that drilling fluid granularity can be realizedChange.
Embodiment 5:
At room temperature, nano-silicon l0g and 800 mesh calcium carbonate 50g is taken, 1000ml drilling fluid (drilling fluid composition are as follows: 5% sodium base is swollen is addedMoisten+15% weight of+0.4%+2.5% polymeric alcohol of ammonium salt+1%SMP+ 0.5%LV-CMC of native+0.2% natural polymersSpar, pH=8) in, high-speed stirred 30min, granularity optimum results such as Fig. 1.