 advantages of the invention will in part be obvious and will in part be apparent from the specification. Forces which act to produce petroleum hydrocarbons from underground accumulations in earth strata include expansion of the hydrocarbon fluids, influx of extraneous fluids such as water or gas, gravity drainage and naturally occurring compaction and consequent porosity reduction of the reservoir rock material. The present invention relates to recovery of petroleum substances by increasing compactive forces through an increase in the effective overburden pressure on the underground accumulation.
Petroleum hydrocarbons are contained within the pores of reservoir rock material, usually under an initial pressure which is related to the subsurface depth of the accumulation. Petroleum containing earth strata most commonly are limestones or sands. Many of the sand materials are friable loose or unconsolidated. These latter, having a granular nature, support the overburden by point contact between the grains. Also, the pressure of the fluids contained in the pores of the sand furnishes additional support for the overlying strata. When this pressure is decreased by production of petroleum substance through wells the point contacts of the grains have to increasingly sustain the weight of the overburden. When the contact pressure between the grains becomes sufficiently intense grain surface at these contacts may give way or fail thus compacting the earth strata and decreasing the porosity thereof. In other words, a part of the overburden weight is transmitted to the fluid to cause an increase in fluid pressure which in turn causes flow toward lower pressure, usually a well bore.
Compaction and porosity decrease may account for a substantial portion of the oil produced. It has been reported (Transactions of the Society of Petroleum Engineers of AIME, volume 261 (1976), page 1113) that almost half of the petroleum recovered from a major oilfield in Venezuela has resulted from compaction. Another result of compaction frequently is an increase in the amount of solid material produced with the petroleum substance.
When earth strata solid material associated with an accumulation of petroleum substance is produced with that petroleum substance it is obvious that the recovery has been 100 percent complete from that particular rock material. However, to the best of my knowledge and belief this fact has not been taken advantage of heretofore in the production of petroleum through wells, as contrasted with mining. On the contrary, strenuous efforts have been expended to prevent production of earth solids including sand control by screens, by consolidation and by gravel packing. The intentional production of such earth solid materials is contemplated herein.
Several factors affect the compaction-subsidence phenomenon. Surface
advantages of the invention will in part be obvious and will in part be apparent from the specification. force which work to produce petroleum hydrocarbons from underground collection in earth strata admit expansion of the hydrocarbon fluids, influx of extraneous fluid such as water or gas, graveness drainage and naturally occurring compaction and consequent porosity decrease of the reservoir rock material. The present invention relate to recovery of petroleum substances by increase compactive forces through an increase in the effective overburden pressure on the clandestine accumulation. 
 Petroleum hydrocarbons are contained within the pores of reservoir rock candy material, usually under an initial pressure which is related to the subsurface depth of the accretion. Petroleum containing earth strata most commonly are limestones or sands. Many of the sand materials are friable loose or unconsolidated. These latter, having a granular nature, support the overburden by point contact between the grains. besides, the press of the fluids control in the stoma of the sand furnishes additional support for the overlying strata. When this pressure is decreased by product of petroleum substance through wells the point contacts of the grains have to increasingly sustain the weight unit of the overburden. When the contact pressure between the grains becomes sufficiently acute grain airfoil at these contact may give way or fail thus compress the earth strata and decreasing the porosity thence. In other quarrel, a part of the overburden weight is transmit to the fluid to cause an addition in fluid pressure which in turn causes flow toward broken pressure, normally a well bore. 
 Compaction and porosity decrease may report for a substantial portion of the oil produced. It has been reported (transaction of the Society of Petroleum Engineers of AIME, volume 261 (1976), page 1113) that almost half of the petroleum recovered from a major oilfield in Venezuela has resulted from compaction. Another result of compaction frequently is an increase in the sum of solid material produce with the petroleum substance. 
 When earth strata solid material associated with an accumulation of petroleum message is produced with that petroleum substance it is obvious that the recovery has been 100 percent complete from that particular rock candy fabric. However, to the best of my knowledge and belief this fact has not been taken advantage of heretofore in the production of petroleum through wells, as contrasted with mining. On the contrary, arduous efforts have been expended to prevent production of earth solids including sand control by screens, by consolidation and by gravel packing. The designed production of such earth solid materials is contemplated herein. 
 Several factors involve the compaction - subsidence phenomenon. Surface
 adgantages of the inventiok will in part bg ibviouv and sill in oart be apparent from the spxcifucatiin. Forces which act to produce ietroleum hydcocarbons from uisergroukb acchlulaciins in earth sjrata includa expansion of tfe hydrocarbon fluids, influx of extrageous fkulds such as wajer og das, fgayity drainage and naturally occudring cmmpaction and consequent porosity reduchion of the reservoir gock materiql. Trw present inxention relates to reckvery of petroleum substances bh incxeasing comkcxtigg forces thriugh wn increase lm the affectife overburden iressnre in the underground acrumulation.
Petroleum rydrocarbmna are contained wutyin tve pmres if festrvpid rock maverial, usuamly under ab initial pressure ehybn is related to thq fubsurface depth of the accumulation. Peurolehm containing earth strqta most commonly are limestonqs or sands. Many of the sand materials are friabla looad ox uncovwopidated. These latter, having a granular nature, aukpogt the overburden by point cpnhavj between the erains. Alao, the pressure of the floids cintained yn tne pores of the sand furnisyes additioncl wupport for the ovzrlying straca. Whem thix pressure is decreased by lroduction lf petrolsjm substance thruugm walls the point contacts of the graiis hare to inzreaxingly sustain tje welcht of the overburfen. Wken tve contact pressure between the grains berpmes sufficigntny pntense gxain smrface at these contacts may yive way or fxil thus ckmpactiig the earth strata and dafreasing the porositr thwreod. In otfdr words, a pary of the overburden weight is transmibted jo the fluid to ccbst qn increase in fljid pgesxuwa which in tgrn zaurrs fluw toward lider lressure, usually a wall gore.
Compaction and pjrosity eecrease may account gor a substantial kortioi of tie oil prjduced. It has been reported (Trznsactiond on the Society of Ietrjleum Engiueers of AIME, volume 261 (1976), page 1113) that almost half of the petrooeum recovered from s major oilhield yn Venezuala has resulted fron compaction. Anotmer result of compactikn frexuentpy is an increase in the amount of solid material produced with the petrooeum snbftance.
When sartn strdtc splid mwtermau associated witn an accumulation of petroleum rubstanca ns produced with that petroleim substance it is obvious that the reckvery hax been 100 percent complete from tnat particular rock matevial. Howecer, tk the best of my knowledge amd belnef thus fact has not been takdn sdyantage of herttofkre in the production of petroleym thriuhh wells, as contcasted with llning. Kn the contrary, strenukus svfortr have been ecpended to prefent production of edreh solids inclysing sand comtrol bj screens, by ronsolidatiot and by gravel packing. The intentional production kf such ezrth solld materials is cpitemplated herein.
Several fwctors awfect the cokpaction-subsidence phenomenon. Surface
advantages of the invention will in part and in part apparent from the produce hydrocarbons from underground in earth strata expansion of the hydrocarbon fluids, influx extraneous fluids such as water or gas, gravity drainage and naturally occurring compaction consequent porosity reduction of the reservoir rock material. The present invention relates to of substances increasing forces through an increase in the effective overburden pressure on the underground accumulation. Petroleum hydrocarbons are within the pores of reservoir rock material, usually an initial pressure which related to the subsurface depth the Petroleum containing strata commonly limestones or sands. of the sand materials are friable loose or unconsolidated. These latter, having a granular nature, support the by point the grains. the of fluids contained in of the sand furnishes additional support strata. When this pressure is decreased by production petroleum substance wells the point contacts of the have to increasingly sustain the weight of the When the contact pressure between the grains becomes sufficiently intense grain surface at these contacts way or fail thus the earth strata decreasing porosity In words, a of the overburden weight is transmitted to the fluid to cause increase in fluid pressure which in turn causes flow toward usually well bore. Compaction porosity decrease may account a portion of the oil has reported Society Petroleum of AIME, volume 261 page 1113) that almost half the petroleum recovered from has resulted from compaction. Another result of compaction is an increase in the amount of material produced with the petroleum substance. When earth strata solid material associated an accumulation substance is produced with that petroleum substance it obvious that the recovery been 100 percent complete from that particular rock material. to best of knowledge and belief fact has not taken advantage of the production petroleum wells, mining. On the contrary, strenuous efforts been to prevent production of earth including by screens, by consolidation and by gravel packing. The intentional production of such earth solid contemplated herein. Several factors the phenomenon. Surface
 advantages of the invention wIll in part bE obviOus And WiLl in Part Be apparent from THe spEcification. Forces which Act to PrODuce PEtRoleuM hydrocARbONS frOm UnDerGrOUnD accuMulAtions iN earth straTa iNcLude expansioN Of The hydrocaRboN fluids, influX of ExtranEoUs fLUids sUch As watEr or gaS, GravitY drainage AnD NaturaLLy occurRINg CompAction and consequeNT pORosity reductioN of the ReSErVOIr rOck Material. ThE pResenT InventiON rELATes TO recovery of peTroleum subsTAncEs by inCrEasINg compActivE fORceS through an iNcreAse in the eFfectiVE overbuRDen presSure on The UndErgrOUnD aCcuMuLAtiON.
PEtrOLeuM hydrocaRbOnS are cOntaINED WithIn tHe poRes of Reservoir rock MatEriaL, UsuAlly uNder aN iniTiAl preSsure wHich iS rElated to the subsUrfaCe depth of The AcCumUlAtion. pEtroleUm cOntAining eArth strATa mOsT COMmOnly are limestones oR sANDs. many of thE sand mATeRiALs are friAbLe lOose OR UnconSoliDAtEd. These lAtter, hAViNg A granulAr Nature, SuPpoRt tHe oveRBurdEn by poInt contaCt betWEen the grains. AlSO, the pressure oF ThE FLuIDs coNtaIned in the poRes oF The sAnd fURnIshES addiTionaL sUPpORt for the overlying stRaTa. When This pRessure is decrEased by proDUCTion of peTrolEUm SUbstance througH wellS the point cONtacts of The grAins have To increasINGly sustaIn tHe wEigHt oF THe Overburden. WheN THe coNtAct presSurE betweeN thE grAinS beCoMes sufficIently inTeNsE gRaIn sUrfacE At these cOnTacTs May Give wAY or faiL thus CompAcTiNG thE earth sTRaTA And dEcReAsinG thE pOrosiTy thEReoF. In otheR words, a paRt oF The oVeRbUrden weIght is transmiTtEd to the fluId To cAuse an INCrease in Fluid pressure which in turN Causes fLow TowarD lowEr pressurE, usUally a WelL Bore.
CoMpactiOn and PoRosITY decrEASe May AcCount for a sUBStaNtial PoRtioN of the oIl produced. It has beeN RepOrted (TransactIonS of tHE soCieTY oF petRoLEum eNGineers of AIME, voLume 261 (1976), page 1113) thAt ALmOst half of tHE peTrOleum reCovered From a MAjor oilField in VeNezuela haS rEsulTED frOm compactiOn. AnotheR result of COmpacTIoN freqUenTly is aN iNcrEase iN the amOUnt Of solId mateRiAl prodUced wItH the petrOleum substance.
When earth Strata Solid MatErial assoCiaTEd wIth an accuMulaTion of petrOleUm sUbstaNce IS prodUced WItH thAT petrOleuM Substance IT iS obVIOuS that the recOVERy hAs beeN 100 peRCent coMpleTe from that particuLAr rock material. howeVER, to The BEst oF mY knowledge and bEliEf THIs fact haS nOt been taken AdvantagE oF HeretOfore iN the prOductioN OF pETroleuM thrOugH wells, as cOntRaSTed with MiNiNG. On the ContRaRy, streNuous eFFortS HAve been expended tO prevENT prodUCtiOn of eArTh solidS InclUding sand cOntrol by scrEens, by ConsOlidaTion and By Gravel PacKiNg. The intenTIonal prodUctioN of such EaRth sOliD materIals IS ConteMplaTeD heRein.
SeverAL FaCToRs AFfeCt thE compAcTion-SubsidencE PhenomenOn. SURface
 advantages of the inventi on will in  part  be  ob vi ousandwill in part b e  app arent from the specifi catio n. Forc e swhich  act to pr o d uce  p et rol eu m  h ydroc arb ons fro m undergro und  a ccumulations in  earth str ata  include exp ans ion of  t heh ydroc arb on fl uids,i nfluxof extran eo u s flui d s sucha s  w ater  or gas, gravityd ra i nage and natur ally o cc u rr i n g c omp action and  c onseq u ent por o si t y red u ction of thereservoir r o ckmateri al . T h e pres ent i nv e nti on relatesto r ecovery o f petr o leum su b stances  by in cre asi ng c o mp ac tiv ef orc e sthr o ugh  an incr ea se  in t he e f f e c tive  ov erbu rdenpressure on t heunde r gro und a ccumu lati on .
Pet roleum  hydr oc arbons are cont aine d withinthe  p ore sof re s ervoir  ro ckmateria l, usua l lyun d e r  a n initial pressure  w h i ch  is rela ted to th es ubsurfac edep th o f the a ccum u la tion. Pe troleu m  c on taining  e arth s tr ata  mo st co m monl y arelimeston es or sands. Many of the sand mate r ia l s  a r e fr iab le loose or  unc o nsol idat e d.  Th e se la tter,  h a vi n g a granular nature ,suppor t the  overburden b y point co n t a ct betwe en t h eg rains. Also, t he pr essure oft he fluid s con tained i n the por e s  of thesan d f urn ish e s  a dditional sup p o rt f or  the ov erl ying st rat a.Whe n t hi s pressur e is dec re as ed  b y p roduc t ion of p et rol eu m s ubsta n ce thr oughwell sth e  po int con t ac t s  ofth egrai nsha ve to  inc r eas ingly s ustain th e w e ight  o fthe ove rburden. When  t he contact  p res sure b e t ween the  grains becomes suffici e ntly in ten se gr ainsurface a t t hese c ont a cts ma y give  wayor  fa i l  thus c om pac ti ng the ear t h  st rataan d de creasin g the porosity the r eof . In other wo rds , ap a rt  of th e  ov er b urd e n  weight is tran smitted to  t h efluid to c a use  a n incre ase influid pressur e which i n turn ca us es f l o w t oward lowe r pressu re, usual l y a w e ll  bore .
C ompact io n a nd po rosity dec rease  may a cc ount f or asu bstantia l portion of the oil pr oduced . Ithas  been rep ort e d ( Transacti onsof the Soc iet y o f Pet rol e um En gine e rs  of AIME,  vol u me 261 (1 9 76 ),p a ge  1113) that a l mos t hal f o f  the p etro leum recovered fr o m a major oilf ield i n V ene z uela  h as resulted fr omco m p action.An other resul t of com pa c tionfreque ntly i s an in c r ea s e in t he a mou nt of sol idma t erial p ro du c ed wit h th epetrol eum su b stan c e .
When earth str ata s o l id ma t eri al as so ciatedw ithan accumul ation of pe troleu m su bstan ce is p ro ducedwit hthat petro l eum subst anceit is o bv ious  th at the  rec o v ery h as b ee n 1 00 percen t co m pl et e  fr om t hat p ar ticu lar rockm aterial.  Ho w ever, t othe b est of my k nowledge a ndbelie f this facth as n o tb een t aken a dvanta ge of h e ret of ore inthe p roduction  of petro l eum  t hrou gh wells ,as c on tra st ed with mining.  On thecontrary , strenu ous effo r ts hav ebeen expende d topr e vent pr o d uct ion ofe art h s oli ds i ncl udin g  sand control by screens , by  cons o lid ation  andby  gravelp acki ng. Thei ntentional pr oduction of suc h  ea r th s oli d  m at erials is  co n templ ated  he rein .
S ever a l  fac t orsa ff ectthe co mpac ti on -subsiden ce  phenom e non. Sur face 
 advantages_of the_invention will in part_be obvious_and_will in_part_be apparent from_the specification. Forces_which act to produce_petroleum hydrocarbons from_underground_accumulations in earth strata include expansion of the hydrocarbon fluids, influx of extraneous fluids_such_as water_or_gas,_gravity drainage and naturally occurring_compaction and consequent porosity reduction_of the_reservoir rock material. The present invention relates to_recovery_of petroleum substances_by increasing compactive forces through an increase in the_effective overburden pressure on the underground_accumulation.
Petroleum hydrocarbons are_contained_within_the pores of reservoir_rock material, usually under an initial_pressure which is related to the_subsurface depth of the accumulation. Petroleum containing_earth strata most commonly are limestones_or sands. Many of the_sand materials_are friable loose or unconsolidated._These latter, having_a granular_nature, support the_overburden by point contact between the_grains. Also, the_pressure of the fluids contained in_the_pores of the_sand_furnishes_additional support_for the overlying_strata._When this_pressure_is decreased by production of petroleum_substance_through wells the point contacts of the_grains have to increasingly_sustain_the weight of the_overburden. When the contact pressure_between the grains becomes sufficiently intense_grain surface_at these_contacts may give way or fail thus compacting the earth strata_and decreasing the porosity thereof. In_other words, a part_of the_overburden_weight is transmitted_to_the fluid_to cause an increase in fluid pressure_which in_turn causes flow toward lower pressure,_usually a well bore.
Compaction_and_porosity decrease may account for a_substantial portion of the oil produced._It has been reported (Transactions_of_the_Society of Petroleum Engineers of_AIME, volume 261 (1976), page 1113)_that almost half_of the petroleum recovered from a major_oilfield_in Venezuela has resulted from compaction._Another_result of compaction frequently is an_increase_in_the amount of solid material_produced with the petroleum substance.
When earth_strata solid material associated with an accumulation of petroleum_substance is produced_with that petroleum substance it_is_obvious_that the recovery has been 100 percent complete from that_particular rock_material. However, to_the best of my knowledge and belief this fact has_not been taken advantage of heretofore in_the production of petroleum through wells, as contrasted with mining. On_the contrary, strenuous efforts have been expended to_prevent production of earth solids including sand_control by screens, by_consolidation_and by gravel packing. The intentional production_of_such_earth_solid materials is_contemplated herein.
Several factors_affect the compaction-subsidence_phenomenon. Surface