SU836340A1

SU836340A1 - Method of treating the near-bottom area of non-uniform formation

Info

Publication number: SU836340A1
Application number: SU792809005A
Authority: SU
Inventors: Борис Зиновьевич Сергеев; Владимир Васильевич Калашнев; Маргарита Николаевна Лебедева; Алла Илларионовна Есипенко
Priority date: 1979-08-13
Filing date: 1979-08-13
Publication date: 1981-06-07

Description

Изобретение относится к области не- ‘ фтедобывающей промышленности, в частности к способам обработки призабойной зоны пласта.The invention relates to the field of the oil and gas industry, in particular to methods for treating the bottom-hole formation zone.

Известен способ обработки призабойной эоны пласта путем закачки в нее ки— ⁵еноты, например, амидосульфоновой [1], Способ недостаточно эффективен из-за невозможности использования его в неоднородных пластах.There is a method of processing bottom-hole aeon of the formation by pumping into it ki- ⁵ raccoons, for example, amidosulfonic [1], The method is not effective enough due to the impossibility of using it in heterogeneous formations.

Известен способ обработки призабойной^wзоны неоднородного пласта, заключающийся в предварительной изоляции высокопроницаемых пропластков и последующей закачке кислоты в низкопроницаемые пропластки [2].There is a method of processing bottom-hole ^w zones of a heterogeneous formation, which consists in preliminary isolation of high-permeability layers and subsequent injection of acid into low-permeability layers [2].

Недостатком способа является его невысокая эффективность.The disadvantage of this method is its low efficiency.

Целью настоящего способа является _мповышение эффективности обработки за счет избирательной изоляции высокопроницаемых пропластков независимо от типа коллектора.The purpose of this process is the increase _m processing efficiency due to selective isolation of highly permeable interlayers regardless of the type collector.

Указанная цель достигается тем, что .перед закачкой кислоты в пласт закачи— · вают смесь раствора полиакриламида и соляной кислоты, а после закачки кислоты раствор щелочи, при этом смесь раствора полиакриламида (ПАА) и соляной киолоты закачивают при следующем соотношении компонентов, вес. %This goal is achieved by the fact that before the acid is injected into the formation, a mixture of a solution of polyacrylamide and hydrochloric acid is injected, and after the acid is injected, an alkali solution, while a mixture of a solution of polyacrylamide (PAA) and hydrochloric acid is injected in the following ratio of components, weight. %

Раствор полиакриламида 50-95Polyacrylamide Solution 50-95

Соляная кислота 5-50Hydrochloric acid 5-50

Пример. После проведения подготовительных работ для кислотной обработки в скважину закачивают расчетный объем рабочего кислотного pap* твора, который залавливается в призабойную зону пласта. При это^и кислотному воздействию подвергаются наиболее проницаемые интервалы пласта. Кислотный раствор выдерживается расчетное время, например, при температуре в пласте 130^сС - в течение 20-30 мин.Example. After carrying out preparatory work for acid treatment, the calculated volume of the working acid pap * solution is pumped into the well, which is captured in the bottomhole formation zone. In this case, the most permeable formation intervals are exposed to acid exposure. The acidic solution is maintained Estimated time, e.g., at a temperature in the reservoir 130 ^{to the} C - for 20-30 min.

Затем в скважину закачивают смесьThen the mixture is pumped into the well.

1,5 % раствора ПАА - 50—95 вес.% и 22% соляной кислоты - 5—50 вес.%. Ко- личество смеси будет от 0,2 до 0,5 ' из расчета 0,1 мАга 1 м фильтровой части пласта. Эту смесь закачивают при давлении не выше давления закачки кислоты в 1-ом случае. Через 1 час в сива — ₅ жину закачивают 2-ю порцию рабочего кислотного раствора при давлении выше, чем в первом случае. При этом кислотному воздействию подвергаются менее проницаемые интервалы пласта. После ю того в скважину закачивают 0,2-0,5 м раствора щелочи (например, каустической Соды) 15-50% концентрации и залавливают в пласт при давлении равном давлению, при котором закачивают 1-й 15 кислотный раствор. Скважину оставляют в закрытом состоянии при этом давлении в течение суток. Затем производят промывку забоя скважины пресной водой в объеме одного цикла и приступают к осво- 20 ению обычными методами.1.5% PAA solution - 50-95 wt.% And 22% hydrochloric acid - 5-50 wt.%. The amount of the mixture will be from 0.2 to 0.5 'at the rate of 0.1 mAh 1 m of the filter part of the formation. This mixture is pumped at a pressure not higher than the acid injection pressure in the 1st case. After 1 hour, a second portion of the working acid solution is pumped into siva - ₅ gina at a pressure higher than in the first case. In this case, less permeable formation intervals are exposed to acid exposure. After that, 0.2–0.5 m alkali solution (for example, caustic Soda) is pumped into the well at a concentration of 15–50% and is captured into the reservoir at a pressure equal to the pressure at which the first 15 acid solution is pumped. The well is left closed at this pressure for a day. Then, the bottom of the well is washed with fresh water in the volume of one cycle and they begin to be rehabilitated using conventional methods.

Способ опробирован в лабоработных условиях Ь филиале СевКавНИПИнефть и покЯзал, что раствор щелочи полностью растворяет осадок ПАА и проницаемость 25 образцов песчаника полностью восстанавливается (на участках, где проводилась временная изоляция).The method was tested under laboratory conditions at the SevKavNIPIneft branch and showed that the alkali solution completely dissolves the PAA precipitate and the permeability of 25 sandstone samples is completely restored (in areas where temporary isolation was carried out).

Способ ' при применении в промысловых условиях будет способствовать повышению 30 производительности скважин.The method ', when applied in the field, will increase the productivity of wells 30.

Данный способ можно и целесообразно использовать при обработке призабойной зоны высокотемпературных, неоднородных по проницаемости пластов для уве- 35 личения их производительности. Изобре— тение дает возможность осуществлять поинтервальную обработку практически в любых типах коллекторов нефти и газа.This method can and should be used when processing the bottomhole zone of high-temperature, heterogeneous permeability formations to increase their productivity. The invention makes it possible to carry out interval processing in practically any type of oil and gas reservoirs.

Claims

The invention relates to the field of the non-heel industry, in particular to methods for o6pa6oTiui of a bottomhole formation layer. A method is known for treating a bottomhole formation zone by pumping a spot into it, for example, amndosupifovoy l. The method is not sufficiently effective due to the impossibility of using it in not homogeneous formations. low-lumen banding 2. The disadvantage of the method is its low (and the efficiency. The purpose of the present method is to increase the processing efficiency Irreversible isolation of high past streams irrespective of reservoir type. This goal is achieved by pumping a mixture of polyacrylamide n hydrochloric acid and a solution of polyacrylamide (PAA) and hydrochloric acid before injection of acid into the formation. Chisels are pumped in the following ratio of components, wt.% Polyacrylamide solution 5O-95 Sol hydroacid 5-50 Preferential. After the preparatory work for acid treatment, pia6o4ero acids are pumped into the well the bottom of the reservoir, which is caught in the near-bottom zone of the formation. When the atom is exposed to acid, the most significant intervals of the formation are exposed. The acidic solution is maintained for an estimated time, for example, at a temperature in the formation for 2O-30 min. Then a mixture of a 1.5% solution of PAA — 5O-95 wt.% And 22% hydrochloric acid — 5-50 wt.% Is pumped into the well. The amount of the mixture will be from 0.2 to 0.5 at the rate of OD of 1 m of the filter part of the formation. This mixture is pumped to hfn pressure not higher than the injection pressure of the acid in the 1st case. After 1 hour, a second portion of the working acid solution is pumped into the well; at a pressure higher than in the first case. In doing so, less effective formation intervals are exposed to acid. After that, O, 2-O, S m of an alkali solution (hydrochloride, caustic water) 15–5 O% concentration and squeeze into the reservoir at a pressure equal to the pressure, u) are pumped into the well, and the 1-acid solution is pumped into it. The well was kept closed at this pressure for 24 hours. Then, the bottom hole is washed with fresh water in the volume of one cycle and proceeds with the development by conventional methods. The method was tested under laboratory conditions in the SevKavNIPInefig branch and showed that the alkali solution completely dissolves the PAA precipitate and the density of sandstone samples is fully restored (in the areas where temporary insulation was carried out). The method of application under the conditions will help to increase the well productivity. This method can and is advisable to use & n when treating the u) of the abnormal zone of high-temperature, non-homogeneous porosity of the layers to increase their 1-performance. The invention makes it possible to carry out interval processing in virtually any type of oil and gas reservoir. Claim 1. A method for treating a bottomhole zone of a non-uniform reservoir, consisting in pre-isolating highly permeable streaks and subsequent injection of acid into low-phytophase seams, which is replicated by the fact that, in order to control the effectiveness of the treatment by irregularly isolating high-grade hfoplasts, of the type of a collector, before injection of acid into the formation, its polyacryl amide solution and co-acid is pumped into the reservoir, and after injection of the acid, alkali is added to TBOp alkali. 2. The method according to claim 1, differing from that with the fact that the mixture of the solution of polnacrylamide and hydrochloric acid is pumped in the following ratio of components / weight. : A solution of polyacrylamide Sol hydrochloric acid 5-5 O, Sources of information taken into account for examination 1. Author's certificate of the USSR N 314883, cl. E 21 B 43/27, 26.03.66.

2. US patent number 3612179, cl. 166-281, pub. 1971.